Introduction

The Carbon class is inherited from the PHP DateTime class.

<?php
namespace Carbon;

class Carbon extends \DateTime
{
    // code here
}

You can see from the code snippet above that the Carbon class is declared in the Carbon namespace. You need to import the namespace to use Carbon without having to provide its fully qualified name each time.

use Carbon\Carbon;

Examples in this documentation will assume you imported classes of the Carbon namespace this way.

If you're using Laravel, you may check our Laravel configuration and best-practices recommendations.

If you're using Symfony, you may check our Symfony configuration and best-practices recommendations.

We also provide CarbonImmutable class extending DateTimeImmutable. The same methods are available on both classes but when you use a modifier on a Carbon instance, it modifies and returns the same instance, when you use it on CarbonImmutable, it returns a new instances with the new value.

$mutable = Carbon::now();
$immutable = CarbonImmutable::now();
$modifiedMutable = $mutable->add(1, 'day');
$modifiedImmutable = CarbonImmutable::now()->add(1, 'day');

var_dump($modifiedMutable === $mutable);             // bool(true)
var_dump($mutable->isoFormat('dddd D'));             // string(8) "Sunday 6"
var_dump($modifiedMutable->isoFormat('dddd D'));     // string(8) "Sunday 6"
// So it means $mutable and $modifiedMutable are the same object
// both set to now + 1 day.
var_dump($modifiedImmutable === $immutable);         // bool(false)
var_dump($immutable->isoFormat('dddd D'));           // string(10) "Saturday 5"
var_dump($modifiedImmutable->isoFormat('dddd D'));   // string(8) "Sunday 6"
// While $immutable is still set to now and cannot be changed and
// $modifiedImmutable is a new instance created from $immutable
// set to now + 1 day.

$mutable = CarbonImmutable::now()->toMutable();
var_dump($mutable->isMutable());                     // bool(true)
var_dump($mutable->isImmutable());                   // bool(false)
$immutable = Carbon::now()->toImmutable();
var_dump($immutable->isMutable());                   // bool(false)
var_dump($immutable->isImmutable());                 // bool(true)

The library also provides CarbonInterface interface extends DateTimeInterface and JsonSerializable, CarbonInterval class extends DateInterval, CarbonTimeZone class extends DateTimeZone and CarbonPeriod class polyfills DatePeriod.

Carbon has all the functions inherited from the base DateTime class. This approach allows you to access the base functionality such as modify, format or getTimestamp.

Now, let's see how cool this documentation page is. Click on the code below:

$dtToronto = Carbon::create(2012, 1, 1, 0, 0, 0, 'America/Toronto');
$dtVancouver = Carbon::create(2012, 1, 1, 0, 0, 0, 'America/Vancouver');
// Try to replace the 4th number (hours) or the last argument (timezone) with
// Europe/Paris for example and see the actual result on the right hand.
// It's alive!

echo $dtVancouver->diffInHours($dtToronto); // -3
// Now, try to double-click on "diffInHours" or "create" to open
// the References panel.
// Once the references panel is open, you can use the search field to
// filter the list or click the (<) button to close it.

Some examples are static snippets, some other are editable (when there is a top right hand corner expand button). You can also click on this button to open the snippet in a new tab. You can double-click on method names in both static and dynamic examples.

Instantiation

There are several different methods available to create a new instance of Carbon. First there is a constructor. It overrides the parent constructor and you are best to read about the first parameter from the PHP manual and understand the date/time string formats it accepts. You'll hopefully find yourself rarely using the constructor but rather relying on the explicit static methods for improved readability.

$carbon = new Carbon();                  // equivalent to Carbon::now()
$carbon = new Carbon('first day of January 2008', 'America/Vancouver');
echo get_class($carbon);                 // 'Carbon\Carbon'

$carbon = new Carbon(new DateTime('first day of January 2008'), new DateTimeZone('America/Vancouver')); // equivalent to previous instance
// You can create Carbon or CarbonImmutable instance from:
//   - string representation
//   - integer timestamp
//   - DateTimeInterface instance (that includes DateTime, DateTimeImmutable or an other Carbon instance)
// All those are available right in the constructor, other creator methods can be found
// in the "Reference" panel searching for "create".

You'll notice above that the timezone (2nd) parameter was passed as a string rather than a \DateTimeZone instance. All DateTimeZone parameters have been augmented so you can pass a DateTimeZone instance, string or integer offset to GMT and the timezone will be created for you. This is shown again in the next example which also introduces the now() function.

$now = Carbon::now(); // will use timezone as set with date_default_timezone_set
// PS: we recommend you to work with UTC as default timezone and only use
// other timezones (such as the user timezone) on display

$nowInLondonTz = Carbon::now(new DateTimeZone('Europe/London'));

// or just pass the timezone as a string
$nowInLondonTz = Carbon::now('Europe/London');
echo $nowInLondonTz->tzName;             // Europe/London
echo "\n";

// or to create a date with a custom fixed timezone offset
$date = Carbon::now('+13:30');
echo $date->tzName;                      // +13:30
echo "\n";

// Get/set minutes offset from UTC
echo $date->utcOffset();                 // 810
echo "\n";

$date->utcOffset(180);

echo $date->tzName;                      // +03:00
echo "\n";
echo $date->utcOffset();                 // 180

If you really love your fluid method calls and get frustrated by the extra line or ugly pair of brackets necessary when using the constructor you'll enjoy the parse method.

echo (new Carbon('first day of December 2008'))->addWeeks(2);     // 2008-12-15 00:00:00
echo "\n";
echo Carbon::parse('first day of December 2008')->addWeeks(2);    // 2008-12-15 00:00:00

The string passed to Carbon::parse or to new Carbon can represent a relative time (next sunday, tomorrow, first day of next month, last year) or an absolute time (first day of December 2008, 2017-01-06). You can test if a string will produce a relative or absolute date with Carbon::hasRelativeKeywords().

$string = 'first day of next month';
if (strtotime($string) === false) {
    echo "'$string' is not a valid date/time string.";
} elseif (Carbon::hasRelativeKeywords($string)) {
    echo "'$string' is a relative valid date/time string, it will returns different dates depending on the current date.";
} else {
    echo "'$string' is an absolute date/time string, it will always returns the same date.";
}

To accompany now(), a few other static instantiation helpers exist to create widely known instances. The only thing to really notice here is that today(), tomorrow() and yesterday(), besides behaving as expected, all accept a timezone parameter and each has their time value set to 00:00:00.

$now = Carbon::now();
echo $now;                               // 2025-07-05 06:05:56
echo "\n";
$today = Carbon::today();
echo $today;                             // 2025-07-05 00:00:00
echo "\n";
$tomorrow = Carbon::tomorrow('Europe/London');
echo $tomorrow;                          // 2025-07-06 00:00:00
echo "\n";
$yesterday = Carbon::yesterday();
echo $yesterday;                         // 2025-07-04 00:00:00

The next group of static helpers are the createXXX() helpers. Most of the static create functions allow you to provide as many or as few arguments as you want and will provide default values for all others. Generally default values are the current date, time or timezone. Higher values will wrap appropriately but invalid values will throw an InvalidArgumentException with an informative message. The message is obtained from an DateTime::getLastErrors() call.

$year = 2000; $month = 4; $day = 19;
$hour = 20; $minute = 30; $second = 15; $tz = 'Europe/Madrid';
echo Carbon::createFromDate($year, $month, $day, $tz)."\n";
echo Carbon::createMidnightDate($year, $month, $day, $tz)."\n";
echo Carbon::createFromTime($hour, $minute, $second, $tz)."\n";
echo Carbon::createFromTimeString("$hour:$minute:$second", $tz)."\n";
echo Carbon::create($year, $month, $day, $hour, $minute, $second, $tz)."\n";

createFromDate() will default the time to now. createFromTime() will default the date to today. create() will default any null parameter to the current respective value. As before, the $tz defaults to the current timezone and otherwise can be a DateTimeZone instance or simply a string timezone value. The only special case is for create() that has minimum value as default for missing argument but default on current value when you pass explicitly null.

$xmasThisYear = Carbon::createFromDate(null, 12, 25);  // Year defaults to current year
$Y2K = Carbon::create(2000, 1, 1, 0, 0, 0); // equivalent to Carbon::createMidnightDate(2000, 1, 1)
$alsoY2K = Carbon::create(1999, 12, 31, 24);
$noonLondonTz = Carbon::createFromTime(12, 0, 0, 'Europe/London');
$teaTime = Carbon::createFromTimeString('17:00:00', 'Europe/London');

try { Carbon::create(1975, 5, 21, 22, -2, 0); } catch(InvalidArgumentException $x) { echo $x->getMessage(); }
// minute must be between 0 and 99, -2 given

// Be careful, as Carbon::createFromDate() default values to current date, it can trigger overflow:
// For example, if we are the 15th of June 2020, the following will set the date on 15:
Carbon::createFromDate(2019, 4); // 2019-04-15
// If we are the 31th of October, as 31th April does not exist, it overflows to May:
Carbon::createFromDate(2019, 4); // 2019-05-01
// That's why you simply should not use Carbon::createFromDate() with only 2 parameters (1 or 3 are safe, but no 2)

Create exceptions occurs on such negative values but not on overflow, to get exceptions on overflow, use createSafe()

echo Carbon::create(2000, 1, 35, 13, 0, 0);
// 2000-02-04 13:00:00
echo "\n";

try {
    Carbon::createSafe(2000, 1, 35, 13, 0, 0);
} catch (\Carbon\Exceptions\InvalidDateException $exp) {
    echo $exp->getMessage();
}
// day : 35 is not a valid value.

Note 1: 2018-02-29 also throws an exception while 2020-02-29 does not since 2020 is a leap year.

Note 2: Carbon::createSafe(2014, 3, 30, 1, 30, 0, 'Europe/London') also produces an exception as this time is in an hour skipped by the daylight saving time.

Note 3: The PHP native API allow to consider there is a year 0 between -1 and 1 even if it doesn't regarding Gregorian calendar. That's why years lower than 1 will throw an exception using createSafe. Check isValid() for year-0 detection.

Carbon::createFromFormat($format, $time, $tz);

createFromFormat() is mostly a wrapper for the base php function DateTime::createFromFormat. The difference being again the $tz argument can be a DateTimeZone instance or a string timezone value. Also, if there are errors with the format this function will call the DateTime::getLastErrors() method and then throw a InvalidArgumentException with the errors as the message.

echo Carbon::createFromFormat('Y-m-d H', '1975-05-21 22')->toDateTimeString(); // 1975-05-21 22:00:00

You can test if a date matches a format for createFromFormat() (e.g. date/time components, modifiers or separators) using Carbon::hasFormatWithModifiers() or Carbon::canBeCreatedFromFormat() which also ensure data is actually enough to create an instance.

var_dump(Carbon::hasFormatWithModifiers('21/05/1975', 'd#m#Y!')); // bool(true)
// As 21 is too high for a month number and day is expected to be formatted "05":
var_dump(Carbon::hasFormatWithModifiers('5/21/1975', 'd#m#Y!')); // bool(false)
// 5 is ok for N format:
var_dump(Carbon::hasFormatWithModifiers('5', 'N')); // bool(true)
// but not enough to create an instance:
var_dump(Carbon::canBeCreatedFromFormat('5', 'N')); // bool(false)
// Both hasFormatWithModifiers() and hasFormat() exist because
// hasFormat() does not interpret modifiers, it checks strictly if ->format() could have produce the given
// string with the given format:
var_dump(Carbon::hasFormat('21/05/1975', 'd#m#Y!')); // bool(false)
var_dump(Carbon::hasFormat('21#05#1975!', 'd#m#Y!')); // bool(true)

You can create instances from unix timestamps. createFromTimestamp() create a Carbon instance equal to the given timestamp and will set the timezone to the given timezone as second parameter, or to UTC if non given (since Carbon 3) (in previous versions it defaulted to date_default_timezone_get()). It supports int, float or string containing one or more numbers (like the one produced by microtime()) so it can also set microseconds with no precision lost. The third, createFromTimestampMs(), accepts a timestamp in milliseconds instead of seconds. Negative timestamps are also allowed.

echo Carbon::createFromTimestamp(-1)->toDateTimeString();                                             // 1969-12-31 23:59:59
echo Carbon::createFromTimestamp(-1.5, 'Europe/London')->toDateTimeString();                          // 1970-01-01 00:59:58
echo Carbon::createFromTimestampUTC(-1)->toDateTimeString();                                          // 1969-12-31 23:59:59
echo Carbon::createFromTimestamp('1601735792.198956', 'Europe/London')->format('Y-m-d\TH:i:s.uP');    // 2020-10-03T15:36:32.198956+01:00
echo Carbon::createFromTimestampUTC('0.198956 1601735792')->format('Y-m-d\TH:i:s.uP');                // 2020-10-03T14:36:32.198956+00:00
echo Carbon::createFromTimestampMs(1)->format('Y-m-d\TH:i:s.uP');                                     // 1970-01-01T00:00:00.001000+00:00
echo Carbon::createFromTimestampMs('1601735792198.956', 'Europe/London')->format('Y-m-d\TH:i:s.uP');  // 2020-10-03T15:36:32.198956+01:00
echo Carbon::createFromTimestampMsUTC('0.956 1601735792198')->format('Y-m-d\TH:i:s.uP');              // 2020-10-03T14:36:32.198956+00:00

You can also create a copy() of an existing Carbon instance. As expected the date, time and timezone values are all copied to the new instance.

$dt = Carbon::now();
echo $dt->diffInYears($dt->copy()->addYear());  // 1

// $dt was unchanged and still holds the value of Carbon:now()

// Without ->copy() it would return 0 because addYear() modify $dt so
// diffInYears() compare $dt with itself:
echo $dt->diffInYears($dt->addYear());  // 0

// Note that this would not happen neither with CarbonImmutable
// When immutable, any add/sub methods return a new instance:
$dt = CarbonImmutable::now();
echo $dt->diffInYears($dt->addYear());  // 1

// Last, when your variable can be either a Carbon or CarbonImmutable,
// You can use avoidMutation() which will copy() only if the given date
// is mutable:
echo $dt->diffInYears($dt->avoidMutation()->addYear());  // 1

You can use nowWithSameTz() on an existing Carbon instance to get a new instance at now in the same timezone.

$meeting = Carbon::createFromTime(19, 15, 00, 'Africa/Johannesburg');

// 19:15 in Johannesburg
echo 'Meeting starts at '.$meeting->format('H:i').' in Johannesburg.';                  // Meeting starts at 19:15 in Johannesburg.
// now in Johannesburg
echo "It's ".$meeting->nowWithSameTz()->format('H:i').' right now in Johannesburg.';    // It's 08:05 right now in Johannesburg.

Finally, if you find yourself inheriting a \DateTime instance from another library, fear not! You can create a Carbon instance via a friendly instance() method. Or use the even more flexible method make() which can return a new Carbon instance from a DateTime, Carbon or from a string, else it just returns null.

$dt = new \DateTime('first day of January 2008'); // <== instance from another API
$carbon = Carbon::instance($dt);
echo get_class($carbon);                               // 'Carbon\Carbon'
echo $carbon->toDateTimeString();                      // 2008-01-01 00:00:00

Carbon 2 (requiring PHP >= 7.1) perfectly supports microseconds. But if you use Carbon 1 and PHP < 7.1, read our section about partial microseconds support.

$date = new DateTime('now');
echo $date->format('u');
// display current microtime in PHP >= 7.1 (expect a bug in PHP 7.1.3 only)
// display 000000 before PHP 7.1

$date = new DateTime('2001-01-01T00:00:00.123456Z');
echo $date->format('u');
// display 123456 in all PHP versions

$date->modify('00:00:00.987654');
echo $date->format('u');
// display 987654 in PHP >= 7.1
// display 123456 before PHP 7.1

Carbon::useMicrosecondsFallback(false);
var_dump(Carbon::isMicrosecondsFallbackEnabled()); // false

echo Carbon::now()->micro; // 0 in PHP < 7.1, microtime in PHP >= 7.1

Carbon::useMicrosecondsFallback(true); // default value
var_dump(Carbon::isMicrosecondsFallbackEnabled()); // true

echo Carbon::now()->micro; // microtime in all PHP version

Localization

With Carbon 2, localization changed a lot, 750 new locales are supported, and we now embed locale formats, day names, month names, ordinal suffixes, meridiem, week start and more. While Carbon 1 provided partial support and relied on third-party like IntlDateFormatter class and language packages for advanced translation, you now benefit of a wide internationalization support. You still use Carbon 1? I hope you would consider to upgrade, version 2 has really cool new features. Otherwise, you can find the version 1 documentation of Localization by clicking here.

You can easily customize translations:

// we recommend to use custom language name/variant
// rather than overriding an existing language
// to avoid conflict such as "en_Boring" in the example below:
$boringLanguage = 'en_Boring';
$translator = \Carbon\Translator::get($boringLanguage);
$translator->setTranslations([
    'day' => ':count boring day|:count boring days',
]);
// as this language starts with "en_" it will inherit from the locale "en"

$date1 = Carbon::create(2018, 1, 1, 0, 0, 0);
$date2 = Carbon::create(2018, 1, 4, 4, 0, 0);

echo $date1->locale($boringLanguage)->diffForHumans($date2); // 3 boring days before

$translator->setTranslations([
    'before' => function ($time) {
        return '['.strtoupper($time).']';
    },
]);

echo $date1->locale($boringLanguage)->diffForHumans($date2); // [3 BORING DAYS]

You can use fallback locales by passing in order multiple ones to locale():

\Carbon\Translator::get('xx')->setTranslations([
    'day' => ':count Xday',
]);
\Carbon\Translator::get('xy')->setTranslations([
    'day' => ':count Yday',
    'hour' => ':count Yhour',
]);

$date = Carbon::now()->locale('xx', 'xy', 'es')->sub('3 days 6 hours 40 minutes');

echo $date->ago(['parts' => 3]); // hace 3 Xday 6 Yhour 40 minutos

In the example above, it will try to find translations in "xx" in priority, then in "xy" if missing, then in "es", so here, you get "Xday" from "xx", "Yhour" from "xy", and "hace" and "minutos" from "es".

Note that you can also use an other translator with Carbon::setTranslator($custom) as long as the given translator implements Symfony\Component\Translation\TranslatorInterface. And you can get the global default translator using Carbon::getTranslator() (and Carbon::setFallbackLocale($custom) and Carbon::getFallbackLocale() for the fallback locale, setFallbackLocale can be called multiple times to get multiple fallback locales) but as those method will change the behavior globally (including third-party libraries you may have in your app), it might cause unexpected results. You should rather customize translation using custom locales as in the example above.

Carbon embed a default translator that extends Symfony\Component\Translation\Translator You can check here the methods we added to it.

$translator = Translator::get('en');
$directories = $translator->getDirectories();
var_dump($directories); // Check actual directory

// Change the whole list
$translator->setDirectories([
    'corporate/translations',
    'users/translations',
]);
// Add one directory to the list
$translator->addDirectory('external/translations/directory');
// Remove one directory from the list
$translator->removeDirectory('users/translations');

// After such a settings change, you could need to clear the cache with `resetMessages`
$translator->resetMessages();

// To restore the initial settings simply recall setDirectories with the original list:
$translator->setDirectories($directories);

$translator = Translator::get();
var_dump($translator->getLocalesFiles()); // /path/to/af.php, /path/to/ar.php, etc.
var_dump($translator->getAvailableLocales()); // af, ar, etc.

// You can also filter files/locales starting with a given prefix:
echo implode(', ', array_map('basename', $translator->getLocalesFiles('fr'))); // fr.php, fr_BE.php, fr_BF.php, fr_BI.php, fr_BJ.php, fr_BL.php, fr_CA.php, fr_CD.php, fr_CF.php, fr_CG.php, fr_CH.php, fr_CI.php, fr_CM.php, fr_DJ.php, fr_DZ.php, fr_FR.php, fr_GA.php, fr_GF.php, fr_GN.php, fr_GP.php, fr_GQ.php, fr_HT.php, fr_KM.php, fr_LU.php, fr_MA.php, fr_MC.php, fr_MF.php, fr_MG.php, fr_ML.php, fr_MQ.php, fr_MR.php, fr_MU.php, fr_NC.php, fr_NE.php, fr_PF.php, fr_PM.php, fr_RE.php, fr_RW.php, fr_SC.php, fr_SN.php, fr_SY.php, fr_TD.php, fr_TG.php, fr_TN.php, fr_VU.php, fr_WF.php, fr_YT.php
echo implode(', ', $translator->getAvailableLocales('fr')); // fr, fr_BE, fr_BF, fr_BI, fr_BJ, fr_BL, fr_CA, fr_CD, fr_CF, fr_CG, fr_CH, fr_CI, fr_CM, fr_DJ, fr_DZ, fr_FR, fr_GA, fr_GF, fr_GN, fr_GP, fr_GQ, fr_HT, fr_KM, fr_LU, fr_MA, fr_MC, fr_MF, fr_MG, fr_ML, fr_MQ, fr_MR, fr_MU, fr_NC, fr_NE, fr_PF, fr_PM, fr_RE, fr_RW, fr_SC, fr_SN, fr_SY, fr_TD, fr_TG, fr_TN, fr_VU, fr_WF, fr_YT

$date = Carbon::parse('2018-02-25 14:00');
echo $date->locale('af_ZA')->meridiem();                     // NM
echo "\n";
echo $date->locale('af_ZA')->meridiem(true);                 // nm
echo "\n";
// Some languages has alternative numbers available:
echo $date->locale('ja_JP')->translateNumber(45);            // 四十五
echo "\n";
// You can also choose a key linked to a numeric value to translate:
echo $date->locale('ja_JP')->getAltNumber('day');            // 二十五
// Note: translations methods like translateNumber and getAltNumber are available
// on CarbonInterval and CarbonPeriod too.
echo "\n";
echo $date->locale('en_SG')->ordinal('day');                 // 25th
echo "\n";
// As ordinal can be gender specific or have context dependency, you can pass the period format as second argument:
$date = Carbon::parse('2018-01-01 14:00');
echo $date->locale('fr_CH')->ordinal('isoWeek', 'w');        // 1re
echo "\n";
echo $date->locale('fr_CH')->ordinal('day', 'd');            // 1er
echo "\n";

$translator = Translator::get('en');
echo Carbon::now()->addSeconds(312)->setLocalTranslator($translator)->diffForHumans(); // 5 minutes from now
echo "\n";

// Below, setMessages will load the english file(s) if available and if not yet loaded in cache, then will change the
// 'from_now' translation
$translator->setMessages('en', [
    'from_now' => 'in :time',
]);
echo Carbon::now()->addSeconds(312)->setLocalTranslator($translator)->diffForHumans(); // in 5 minutes
echo "\n";
echo $translator->getMessages('en')['from_now']; // in :time

You can check what's supported with the following methods:

echo implode(', ', array_slice(Carbon::getAvailableLocales(), 0, 3)).'...';      // aa, aa_DJ, aa_ER...

// Support diff syntax (before, after, from now, ago)
var_dump(Carbon::localeHasDiffSyntax('en'));                                     // bool(true)
var_dump(Carbon::localeHasDiffSyntax('zh_TW'));                                  // bool(true)
// Support 1-day diff words (just now, yesterday, tomorrow)
var_dump(Carbon::localeHasDiffOneDayWords('en'));                                // bool(true)
var_dump(Carbon::localeHasDiffOneDayWords('zh_TW'));                             // bool(true)
// Support 2-days diff words (before yesterday, after tomorrow)
var_dump(Carbon::localeHasDiffTwoDayWords('en'));                                // bool(true)
var_dump(Carbon::localeHasDiffTwoDayWords('zh_TW'));                             // bool(false)
// Support short units (1y = 1 year, 1mo = 1 month, etc.)
var_dump(Carbon::localeHasShortUnits('en'));                                     // bool(true)
var_dump(Carbon::localeHasShortUnits('zh_TW'));                                  // bool(false)
// Support period syntax (X times, every X, from X, to X)
var_dump(Carbon::localeHasPeriodSyntax('en'));                                   // bool(true)
var_dump(Carbon::localeHasPeriodSyntax('zh_TW'));                                // bool(false)

So, here is the new recommended way to handle internationalization with Carbon.

$date = Carbon::now()->locale('fr_FR');

echo $date->locale();            // fr_FR
echo "\n";
echo $date->diffForHumans();     // il y a 0 seconde
echo "\n";
echo $date->monthName;           // juillet
echo "\n";
echo $date->isoFormat('LLLL');   // samedi 5 juillet 2025 06:05

The ->locale() method only change the language for the current instance and has precedence over global settings. We recommend you this approach so you can't have conflict with other places or third-party libraries that could use Carbon. Nevertheless, to avoid calling ->locale() each time, you can use factories.

// Let say Martin from Paris and John from Chicago play chess
$martinDateFactory = new Factory([
    'locale' => 'fr_FR',
    'timezone' => 'Europe/Paris',
]);
$johnDateFactory = new Factory([
    'locale' => 'en_US',
    'timezone' => 'America/Chicago',
]);
// Each one will see date in his own language and timezone

// When Martin moves, we display things in French, but we notify John in English:
$gameStart = Carbon::parse('2018-06-15 12:34:00', 'UTC');
$move = Carbon::now('UTC');
$toDisplay = $martinDateFactory->make($gameStart)->isoFormat('lll')."\n".
    $martinDateFactory->make($move)->calendar()."\n";
$notificationForJohn = $johnDateFactory->make($gameStart)->isoFormat('lll')."\n".
    $johnDateFactory->make($move)->calendar()."\n";
echo $toDisplay;
/*
15 juin 2018 14:34
Aujourd’hui à 08:05
*/

echo $notificationForJohn;
/*
Jun 15, 2018 7:34 AM
Today at 1:05 AM
*/

You can call any static Carbon method on a factory (make, now, yesterday, tomorrow, parse, create, etc.) Factory (and FactoryImmutable that generates CarbonImmutable instances) are the best way to keep things organized and isolated. As often as possible we recommend you to work with UTC dates, then apply locally (or with a factory) the timezone and the language before displaying dates to the user.

What factory actually do is using the method name as static constructor then call settings() method which is a way to group in one call settings of locale, timezone, months/year overflow, etc. (See references for complete list.)

$factory = new Factory([
    'locale' => 'fr_FR',
    'timezone' => 'Europe/Paris',
]);
$factory->now(); // You can recall $factory as needed to generate new instances with same settings
// is equivalent to:
Carbon::now()->settings([
    'locale' => 'fr_FR',
    'timezone' => 'Europe/Paris',
]);
// Important note: timezone setting calls ->shiftTimezone() and not ->setTimezone(),
// It means it does not just set the timezone, but shift the time too:
echo Carbon::today()->setTimezone('Asia/Tokyo')->format('d/m G\h e');        // 05/07 9h Asia/Tokyo
echo "\n";
echo Carbon::today()->shiftTimezone('Asia/Tokyo')->format('d/m G\h e');      // 05/07 0h Asia/Tokyo

// You can find back which factory created a given object:
$a = $factory->now();
$b = Carbon::now();
var_dump($a->getClock()->unwrap() === $factory);  // bool(true)
var_dump($b->getClock());                         // NULL

settings() also allow to pass local macros:

$date = Carbon::parse('Today 12:34:56')->settings([
    'macros' => [
        'lastSecondDigit' => fn () => self::this()->second % 10,
    ],
]);

echo $date->lastSecondDigit();                         // 6
var_dump($date->hasLocalMacro('lastSecondDigit'));     // bool(true)
// You can also retrieve the macro closure using ->getLocalMacro('lastSecondDigit')

Factory settings can be changed afterward with setSettings(array $settings) or to merge new settings with existing ones mergeSettings(array $settings) and the class to generate can be initialized as the second argument of the construct then changed later with setClassName(string $className).

$factory = new Factory(['locale' => 'ja'], CarbonImmutable::class);
var_dump($factory->now()->locale);                                           // string(2) "ja"
var_dump(get_class($factory->now()));                                        // string(22) "Carbon\CarbonImmutable"

class MyCustomCarbonSubClass extends Carbon { /* ... */ }
$factory
    ->setSettings(['locale' => 'zh_CN'])
    ->setClassName(MyCustomCarbonSubClass::class);
var_dump($factory->now()->locale);                                           // string(5) "zh_CN"
var_dump(get_class($factory->now()));                                        // string(22) "MyCustomCarbonSubClass"

Previously there was Carbon::setLocale that set globally the locale. But as for our other static setters, we highly discourage you to use it. It breaks the principle of isolation because the configuration will apply for every class that uses Carbon.

->isoFormat(string $format): string use ISO format rather than PHP-specific format and use inner translations rather than language packages you need to install on every machine where you deploy your application. isoFormat method is compatible with momentjs format method, it means you can use same format strings as you may have used in moment from front-end or node.js. Here are some examples:

$date = Carbon::parse('2018-06-15 17:34:15.984512', 'UTC');
echo $date->isoFormat('MMMM Do YYYY, h:mm:ss a'); // June 15th 2018, 5:34:15 pm
echo "\n";
echo $date->isoFormat('dddd');           // Friday
echo "\n";
echo $date->isoFormat('MMM Do YY');      // Jun 15th 18
echo "\n";
echo $date->isoFormat('YYYY [escaped] YYYY'); // 2018 escaped 2018

You can also create date from ISO formatted strings:

$date = Carbon::createFromIsoFormat('!YYYY-MMMM-D h:mm:ss a', '2019-January-3 6:33:24 pm', 'UTC');
echo $date->isoFormat('M/D/YY HH:mm'); // 1/3/19 18:33

->isoFormat use contextualized methods for day names and month names as they can have multiple forms in some languages, see the following examples:

$date = Carbon::parse('2018-03-16')->locale('uk');
echo $date->getTranslatedDayName('[в] dddd'); // п’ятницю
// By providing a context, we're saying translate day name like in a format such as [в] dddd
// So the context itself has to be translated first consistently.
echo "\n";
echo $date->getTranslatedDayName('[наступної] dddd'); // п’ятниці
echo "\n";
echo $date->getTranslatedDayName('dddd, MMM'); // п’ятниця
echo "\n";
// The same goes for short/minified variants:
echo $date->getTranslatedShortDayName('[наступної] dd'); // пт
echo "\n";
echo $date->getTranslatedMinDayName('[наступної] ddd'); // пт
echo "\n";

// And the same goes for months
$date->locale('ru');
echo $date->getTranslatedMonthName('Do MMMM'); // марта
echo "\n";
echo $date->getTranslatedMonthName('MMMM YYYY'); // март
echo "\n";
// Short variant
echo $date->getTranslatedShortMonthName('Do MMM'); // мар
echo "\n";
echo $date->getTranslatedShortMonthName('MMM YYYY'); // мар
echo "\n";

// And so you can force a different context to get those variants:
echo $date->isoFormat('Do MMMM');        // 16-го марта
echo "\n";
echo $date->isoFormat('MMMM YYYY');      // март 2018
echo "\n";
echo $date->isoFormat('Do MMMM', 'MMMM YYYY'); // 16-го март
echo "\n";
echo $date->isoFormat('MMMM YYYY', 'Do MMMM'); // марта 2018
echo "\n";

Here is the complete list of available replacements (examples given with $date = Carbon::parse('2017-01-05 17:04:05.084512');):

Some macro-formats are also available. Here are examples of each in some languages:

When you use macro-formats with createFromIsoFormat you can specify a locale to select which language the macro-format should be searched in.

$date = Carbon::createFromIsoFormat('LLLL', 'Monday 11 March 2019 16:28', null, 'fr');
echo $date->isoFormat('M/D/YY HH:mm'); // 3/11/19 16:28

Another usefull translated method is calendar($referenceTime = null, array $formats = []): string:

$date = CarbonImmutable::now();
echo $date->calendar();                                      // Today at 6:05 AM
echo "\n";
echo $date->sub('1 day 3 hours')->calendar();                // Yesterday at 3:05 AM
echo "\n";
echo $date->sub('3 days 10 hours 23 minutes')->calendar();   // Last Tuesday at 7:42 PM
echo "\n";
echo $date->sub('8 days')->calendar();                       // 06/27/2025
echo "\n";
echo $date->add('1 day 3 hours')->calendar();                // Tomorrow at 9:05 AM
echo "\n";
echo $date->add('3 days 10 hours 23 minutes')->calendar();   // Tuesday at 4:28 PM
echo "\n";
echo $date->add('8 days')->calendar();                       // 07/13/2025
echo "\n";
echo $date->locale('fr')->calendar();                        // Aujourd’hui à 06:05

If you know momentjs, then it works the same way. You can pass a reference date as second argument, else now is used. And you can customize one or more formats using the second argument (formats to pass as array keys are: sameDay, nextDay, nextWeek, lastDay, lastWeek and sameElse):

$date1 = CarbonImmutable::parse('2018-01-01 12:00:00');
$date2 = CarbonImmutable::parse('2018-01-02 8:00:00');

echo $date1->calendar($date2, [
    'lastDay' => '[Previous day at] LT',
]);
// Previous day at 12:00 PM

Click here to get an overview of the 280 locales (and 823 regional variants) supported by the last Carbon version:

If you can add missing translations or missing languages, please go to translation tool, your help is welcome.

Note that if you use Laravel, the locale will be automatically set according to current last App:setLocale execution. So diffForHumans, isoFormat, translatedFormat and localized properties such as ->dayName or ->monthName will be localized transparently.

All Carbon, CarbonImmutable, CarbonInterval or CarbonPeriod instances are linked by default to a Carbon\Translator instance handled by FactoryImmutable::getDefaultInstance() (The one changing when calling the static method ::setLocale() on one of those classes). You can get and/or change it using getLocalTranslator()/setLocalTranslator(Translator $translator).

If you prefer the date() pattern, you can use translatedFormat() which works like format() but translate the string using the current locale.

$date = Carbon::parse('2018-03-16 15:45')->locale('uk');

echo $date->translatedFormat('g:i a l jS F Y'); // 3:45 дня п’ятниця 16-го березня 2018

Be warned that some letters like W are not supported because they are not safely translatable and translatedFormat offers shorter syntax but less possibilities than isoFormat().

You can customize the behavior of the format() method to use any other method or a custom one instead of the native method from the PHP DateTime class:

$date = Carbon::parse('2018-03-16 15:45')->locale('ja');

echo $date->format('g:i a l jS F Y');    // 3:45 pm Friday 16th March 2018
echo "\n";

$date->settings(['formatFunction' => 'translatedFormat']);

echo $date->format('g:i a l jS F Y');    // 3:45 午後 金曜日 16日 3月 2018
echo "\n";

$date->settings(['formatFunction' => 'isoFormat']);

echo $date->format('LL');                // 2018年3月16日
echo "\n";

// When you set a custom format() method you still can access the native method using rawFormat()
echo $date->rawFormat('D');              // Fri

You can translate a string from a language to another using dates translations available in Carbon:

echo Carbon::translateTimeString('mercredi 8 juillet', 'fr', 'nl');
// woensdag 8 juli
echo "\n";

// You can select translations to use among available constants:
// - CarbonInterface::TRANSLATE_MONTHS
// - CarbonInterface::TRANSLATE_DAYS
// - CarbonInterface::TRANSLATE_UNITS
// - CarbonInterface::TRANSLATE_MERIDIEM
// - CarbonInterface::TRANSLATE_ALL (all above)
// You can combine them with pipes: like below (translate units and days but not months and meridiem):
echo Carbon::translateTimeString('mercredi 8 juillet + 3 jours', 'fr', 'nl', CarbonInterface::TRANSLATE_DAYS | CarbonInterface::TRANSLATE_UNITS);
// woensdag 8 juillet + 3 dagen

If input locale is not specified, Carbon::getLocale() is used instead. If output locale is not specified, "en" is used instead. You also can translate using the locale of the instance with:

echo Carbon::now()->locale('fr')->translateTimeStringTo('mercredi 8 juillet + 3 jours', 'nl');
// woensdag 8 juli + 3 dagen

You can use strings in any language directly to create a date object with parseFromLocale:

$date = Carbon::parseFromLocale('mercredi 6 mars 2019 + 3 jours', 'fr', 'UTC'); // timezone is optional
// 'fr' stands for French but can be replaced with any locale code.
// if you don't pass the locale parameter, Carbon::getLocale() (current global locale) is used.

echo $date->isoFormat('LLLL'); // Saturday, March 9, 2019 12:00 AM

You can also use "today", "today at 8:00", "yesterday", "after tomorrow", etc. equivalents in the given language.

Or with custom format using createFromLocaleFormat (use the date() pattern for replacements):

$date = Carbon::createFromLocaleFormat('!d/F/y', 'fr', '25/Août/19', 'Europe/Paris'); // timezone is optional

echo $date->isoFormat('LLLL'); // Sunday, August 25, 2019 12:00 AM

The equivalent method using ISO format is createFromLocaleIsoFormat:

$date = Carbon::createFromLocaleIsoFormat('!DD/MMMM/YY', 'fr', '25/Août/19', 'Europe/Paris'); // timezone is optional

echo $date->isoFormat('LLLL'); // Sunday, August 25, 2019 12:00 AM

To get some interesting info about languages (such as complete ISO name or native name, region (for example to be displayed in a languages selector), you can use getAvailableLocalesInfo.

$zhTwInfo = Carbon::getAvailableLocalesInfo()['zh_TW'];
$srCyrlInfo = Carbon::getAvailableLocalesInfo()['sr_Cyrl'];
$caInfo = Carbon::getAvailableLocalesInfo()['ca'];

var_dump($zhTwInfo->getId());                      // string(5) "zh_TW"
var_dump($zhTwInfo->getNames());
/*
array(2) {
  ["isoName"]=>
  string(7) "Chinese"
  ["nativeName"]=>
  string(38) "中文 (Zhōngwén), 汉语, 漢語"
}
*/
var_dump($zhTwInfo->getCode());                    // string(2) "zh"
var_dump($zhTwInfo->getVariant());                 // NULL
var_dump($srCyrlInfo->getVariant());               // string(4) "Cyrl"
var_dump($zhTwInfo->getVariantName());             // NULL
var_dump($srCyrlInfo->getVariantName());           // string(8) "Cyrillic"
var_dump($zhTwInfo->getRegion());                  // string(2) "TW"
var_dump($srCyrlInfo->getRegion());                // NULL
var_dump($zhTwInfo->getRegionName());              // string(6) "Taiwan"
var_dump($srCyrlInfo->getRegionName());            // NULL
var_dump($zhTwInfo->getFullIsoName());             // string(7) "Chinese"
var_dump($caInfo->getFullIsoName());               // string(18) "Catalan, Valencian"
var_dump($zhTwInfo->getFullNativeName());          // string(38) "中文 (Zhōngwén), 汉语, 漢語"
var_dump($caInfo->getFullNativeName());            // string(18) "català, valencià"
var_dump($zhTwInfo->getIsoName());                 // string(7) "Chinese"
var_dump($caInfo->getIsoName());                   // string(7) "Catalan"
var_dump($zhTwInfo->getNativeName());              // string(20) "中文 (Zhōngwén)"
var_dump($caInfo->getNativeName());                // string(7) "català"
var_dump($zhTwInfo->getIsoDescription());          // string(16) "Chinese (Taiwan)"
var_dump($srCyrlInfo->getIsoDescription());        // string(18) "Serbian (Cyrillic)"
var_dump($caInfo->getIsoDescription());            // string(7) "Catalan"
var_dump($zhTwInfo->getNativeDescription());       // string(29) "中文 (Zhōngwén) (Taiwan)"
var_dump($srCyrlInfo->getNativeDescription());     // string(34) "српски језик (Cyrillic)"
var_dump($caInfo->getNativeDescription());         // string(7) "català"
var_dump($zhTwInfo->getFullIsoDescription());      // string(16) "Chinese (Taiwan)"
var_dump($srCyrlInfo->getFullIsoDescription());    // string(18) "Serbian (Cyrillic)"
var_dump($caInfo->getFullIsoDescription());        // string(18) "Catalan, Valencian"
var_dump($zhTwInfo->getFullNativeDescription());   // string(47) "中文 (Zhōngwén), 汉语, 漢語 (Taiwan)"
var_dump($srCyrlInfo->getFullNativeDescription()); // string(34) "српски језик (Cyrillic)"
var_dump($caInfo->getFullNativeDescription());     // string(18) "català, valencià"

$srCyrlInfo->setIsoName('foo, bar')->setNativeName('biz, baz');
var_dump($srCyrlInfo->getIsoName());               // string(3) "foo"
var_dump($srCyrlInfo->getFullIsoName());           // string(8) "foo, bar"
var_dump($srCyrlInfo->getFullIsoDescription());    // string(19) "foo, bar (Cyrillic)"
var_dump($srCyrlInfo->getNativeName());            // string(3) "biz"
var_dump($srCyrlInfo->getFullNativeName());        // string(8) "biz, baz"
var_dump($srCyrlInfo->getFullNativeDescription()); // string(19) "biz, baz (Cyrillic)"

// You can also access directly regions/languages lists:
var_dump(\Carbon\Language::all()['zh']);
/*
array(2) {
  ["isoName"]=>
  string(7) "Chinese"
  ["nativeName"]=>
  string(38) "中文 (Zhōngwén), 汉语, 漢語"
}
*/
var_dump(\Carbon\Language::regions()['TW']);
/*
string(6) "Taiwan"
*/

If ever you have to change globally the locale for a particular process, you should use executeWithLocale to encapsulate this process. This way, even if an exception is thrown the global locale with be set back to its previous value.

Carbon::executeWithLocale('fr', function () {
    echo CarbonInterval::create(2, 1)->forHumans() . "\n";
    echo Carbon::parse('-2 hours')->diffForHumans();
});
/*
2 ans 1 mois
il y a 2 heures
*/

Please let me close this section by thanking some projects that helped us a lot to support more locales, and internationalization features:

• jenssegers/date: many features were in this project that extends Carbon before being in Carbon itself.
• momentjs: many features are inspired by momentjs and made to be compatible with this front-side pair project.
• glibc was a strong base for adding and checking languages.
• svenfuchs/rails-i18n also helped to add and check languages.
• We used glosbe.com a lot to check translations and fill blanks.

Testing Aids

The testing methods allow you to set a Carbon instance (real or mock) to be returned when a "now" instance is created. The provided instance will be used when retrieving any relative time from Carbon (now, today, yesterday, next month, etc.)

$knownDate = Carbon::create(2001, 5, 21, 12);          // create testing date
Carbon::setTestNow($knownDate);                        // set the mock (of course this could be a real mock object)
echo Carbon::getTestNow();                             // 2001-05-21 12:00:00
echo Carbon::now();                                    // 2001-05-21 12:00:00
echo new Carbon();                                     // 2001-05-21 12:00:00
echo new Carbon('now');                                // 2001-05-21 12:00:00
echo Carbon::parse('now');                             // 2001-05-21 12:00:00
echo Carbon::create(2001, 4, 21, 12)->diffForHumans(); // 1 month ago

// This will trigger an actual sleep(3) in prod, but when time is mocked,
// This will set the test-now to 3 seconds later:
Carbon::sleep(3);
echo Carbon::now();                                    // 2001-05-21 12:00:03

var_dump(Carbon::hasTestNow());                        // bool(true)
Carbon::setTestNow();                                  // clear the mock
var_dump(Carbon::hasTestNow());                        // bool(false)
echo Carbon::now();                                    // 2025-07-05 06:05:56
// Instead of mock and clear mock, you also can use withTestNow():

Carbon::withTestNow('2010-09-15', static function () {
    echo Carbon::now();
});                                                    // 2010-09-15 00:00:00

A more meaning full example:

class SeasonalProduct
{
    protected $price;

    public function __construct($price)
    {
        $this->price = $price;
    }

    public function getPrice() {
        $multiplier = 1;
        if (Carbon::now()->month == 12) {
            $multiplier = 2;
        }

        return $this->price * $multiplier;
    }
}

$product = new SeasonalProduct(100);
Carbon::setTestNow(Carbon::parse('first day of March 2000'));
echo $product->getPrice();                                             // 100
Carbon::setTestNow(Carbon::parse('first day of December 2000'));
echo $product->getPrice();                                             // 200
Carbon::setTestNow(Carbon::parse('first day of May 2000'));
echo $product->getPrice();                                             // 100
Carbon::setTestNow();

Relative phrases are also mocked according to the given "now" instance.

$knownDate = Carbon::create(2001, 5, 21, 12);          // create testing date
Carbon::setTestNow($knownDate);                        // set the mock
echo new Carbon('tomorrow');                           // 2001-05-22 00:00:00  ... notice the time !
echo new Carbon('yesterday');                          // 2001-05-20 00:00:00
echo new Carbon('next wednesday');                     // 2001-05-23 00:00:00
echo new Carbon('last friday');                        // 2001-05-18 00:00:00
echo new Carbon('this thursday');                      // 2001-05-24 00:00:00
Carbon::setTestNow();                                  // always clear it !

Since Carbon 2.56.0, setTestNow() no longer impact the timezone of the Carbon::now() instance you'll get. This was done because in real life, Carbon::now() returns a date with the timezone from date_default_timezone_get(). And tests should reflect this.

You can use setTestNowAndTimezone() to mock the time and change the default timezone using date_default_timezone_set():

Carbon::setTestNowAndTimezone(Carbon::parse('2022-01-24 10:45 America/Toronto'));
// or
Carbon::setTestNowAndTimezone('2022-01-24 10:45', 'America/Toronto');
echo Carbon::now()->format('Y-m-d e'); // 2022-01-24 America/Toronto
Carbon::setTestNow(); // clear time mock
date_default_timezone_set('UTC'); // restore default timezone

The list of words that are considered to be relative modifiers are:

• +
• -
• ago
• first
• next
• last
• this
• today
• tomorrow
• yesterday

Be aware that similar to the next(), previous() and modify() methods some of these relative modifiers will set the time to 00:00:00.

Carbon::parse($time, $tz) and new Carbon($time, $tz) both can take a timezone as second argument.

echo Carbon::parse('2012-9-5 23:26:11.223', 'Europe/Paris')->timezone->getName(); // Europe/Paris

See Carbonite for more advanced Carbon testing features.

Carbonite is an additional package you can easily install using composer: composer require --dev kylekatarnls/carbonite then use to travel times in your unit tests as you would tell a story:

Add use Carbon\Carbonite; import at the top of the file.

$holidays = CarbonPeriod::create('2019-12-23', '2020-01-06', CarbonPeriod::EXCLUDE_END_DATE);

Carbonite::freeze('2019-12-22'); // Freeze the time to a given date

var_dump($holidays->isStarted());     // bool(false)

// Then go to anytime:
Carbonite::elapse('1 day');

var_dump($holidays->isInProgress());  // bool(true)

Carbonite::jumpTo('2020-01-05 22:00');

var_dump($holidays->isEnded());       // bool(false)

Carbonite::elapse('2 hours');

var_dump($holidays->isEnded());       // bool(true)

Carbonite::rewind('1 microsecond');

var_dump($holidays->isEnded());       // bool(false)

Carbonite::release(); // Release time after each test

Getters

The getters are implemented via PHP's __get() method. This enables you to access the value as if it was a property rather than a function call.

$dt = Carbon::parse('2012-10-5 23:26:11.123789');

// These getters specifically return integers, ie intval()
var_dump($dt->year);                                         // int(2012)
var_dump($dt->month);                                        // int(10)
var_dump($dt->day);                                          // int(5)
var_dump($dt->hour);                                         // int(23)
var_dump($dt->minute);                                       // int(26)
var_dump($dt->second);                                       // int(11)
var_dump($dt->micro);                                        // int(123789)
// dayOfWeek returns a number between 0 (sunday) and 6 (saturday)
var_dump($dt->dayOfWeek);                                    // int(5)
// dayOfWeekIso returns a number between 1 (monday) and 7 (sunday)
var_dump($dt->dayOfWeekIso);                                 // int(5)
var_dump($dt->englishDayOfWeek);                             // string(6) "Friday"
var_dump($dt->shortEnglishDayOfWeek);                        // string(3) "Fri"
var_dump($dt->locale('de')->dayName);                        // string(7) "Freitag"
var_dump($dt->locale('de')->shortDayName);                   // string(3) "Fr."
var_dump($dt->locale('de')->minDayName);                     // string(2) "Fr"
var_dump($dt->englishMonth);                                 // string(7) "October"
var_dump($dt->shortEnglishMonth);                            // string(3) "Oct"
var_dump($dt->locale('de')->monthName);                      // string(7) "Oktober"
var_dump($dt->locale('de')->shortMonthName);                 // string(3) "Okt"

var_dump($dt->dayOfYear);                                    // int(279)
var_dump($dt->weekNumberInMonth);                            // int(1)
// weekNumberInMonth consider weeks from monday to sunday, so the week 1 will
// contain 1 day if the month start with a sunday, and up to 7 if it starts with a monday
var_dump($dt->weekOfMonth);                                  // int(1)
// weekOfMonth will returns 1 for the 7 first days of the month, then 2 from the 8th to
// the 14th, 3 from the 15th to the 21st, 4 from 22nd to 28th and 5 above
var_dump($dt->weekOfYear);                                   // int(40)
var_dump($dt->daysInMonth);                                  // int(31)
var_dump($dt->timestamp);                                    // int(1349479571)
var_dump($dt->getTimestamp());                               // int(1349479571)
// Millisecond-precise timestamp as int
var_dump($dt->getTimestampMs());                             // int(1349479571124)
// Millisecond-precise timestamp as float (useful to pass it to JavaScript)
var_dump($dt->valueOf());                                    // float(1349479571124)
// Custom-precision timestamp
var_dump($dt->getPreciseTimestamp(6));                       // float(1349479571123789)
var_dump(Carbon::createFromDate(1975, 5, 21)->age);          // int(50) calculated vs now in the same tz
var_dump($dt->quarter);                                      // int(4)

// Returns an int of seconds difference from UTC (+/- sign included)
var_dump(Carbon::createFromTimestampUTC(0)->offset);         // int(0)
var_dump(Carbon::createFromTimestamp(0, 'Europe/Paris')->offset);                // int(3600)
var_dump(Carbon::createFromTimestamp(0, 'Europe/Paris')->getOffset());           // int(3600)

// Returns an int of hours difference from UTC (+/- sign included)
var_dump(Carbon::createFromTimestamp(0, 'Europe/Paris')->offsetMinutes);         // int(60)
var_dump(Carbon::createFromTimestamp(0, 'Europe/Paris')->offsetHours);           // int(1)

// Returns timezone offset as string
var_dump(Carbon::createFromTimestamp(0, 'Europe/Paris')->getOffsetString());     // string(6) "+01:00"

// Returns timezone as CarbonTimeZone
var_dump(Carbon::createFromTimestamp(0, 'Europe/Paris')->getTimezone());
/* object(Carbon\CarbonTimeZone)#792 (3) {
  ["clock":"Carbon\CarbonTimeZone":private]=>
  NULL
  ["timezone_type"]=>
  int(3)
  ["timezone"]=>
  string(12) "Europe/Paris"
} */

// Indicates if day light savings time is on
var_dump(Carbon::createFromDate(2012, 1, 1)->dst);           // bool(false)
var_dump(Carbon::createFromDate(2012, 9, 1)->dst);           // bool(false)
var_dump(Carbon::createFromDate(2012, 9, 1)->isDST());       // bool(false)

// Indicates if the instance is in the same timezone as the local timezone
var_dump(Carbon::now()->local);                              // bool(true)
var_dump(Carbon::now('America/Vancouver')->local);           // bool(false)
var_dump(Carbon::now()->isLocal());                          // bool(true)
var_dump(Carbon::now('America/Vancouver')->isLocal());       // bool(false)
var_dump(Carbon::now()->isUtc());                            // bool(true)
var_dump(Carbon::now('America/Vancouver')->isUtc());         // bool(false)
// can also be written ->isUTC()

// Indicates if the instance is in the UTC timezone
var_dump(Carbon::now()->utc);                                // bool(true)
// London is not UTC on summer time
var_dump(Carbon::parse('2018-10-01', 'Europe/London')->utc); // bool(false)
// London is UTC on winter time
var_dump(Carbon::parse('2018-11-01', 'Europe/London')->utc); // bool(true)
var_dump(Carbon::createFromTimestampUTC(0)->utc);            // bool(true)

// Gets the DateTimeZone instance
echo get_class(Carbon::now()->timezone);                     // Carbon\CarbonTimeZone
echo "\n";
echo get_class(Carbon::now()->tz);                           // Carbon\CarbonTimeZone
echo "\n";

// Gets the DateTimeZone instance name, shortcut for ->timezone->getName()
echo Carbon::now()->timezoneName;                            // UTC
echo "\n";
echo Carbon::now()->tzName;                                  // UTC
echo "\n";

// You can get any property dynamically too:
$unit = 'second';
var_dump(Carbon::now()->get($unit));                         // int(56)
// equivalent to:
var_dump(Carbon::now()->$unit);                              // int(56)
// If you have plural unit name, use singularUnit()
$unit = Carbon::singularUnit('seconds');
var_dump(Carbon::now()->get($unit));                         // int(56)
// Prefer using singularUnit() because some plurals are not the word with S:
var_dump(Carbon::pluralUnit('century'));                     // string(9) "centuries"
var_dump(Carbon::pluralUnit('millennium'));                  // string(9) "millennia"

Setters

The following setters are implemented via PHP's __set() method. Its good to take note here that none of the setters, with the obvious exception of explicitly setting the timezone, will change the timezone of the instance. Specifically, setting the timestamp will not set the corresponding timezone to UTC.

$dt = Carbon::now();

$dt->year = 1975;
$dt->month = 13;             // would force year++ and month = 1
$dt->month = 5;
$dt->day = 21;
$dt->hour = 22;
$dt->minute = 32;
$dt->second = 5;

$dt->timestamp = 169957925;  // This will not change the timezone
// Same as:
$dt->setTimestamp(169957925);
$dt->timestamp(169957925);

// Set the timezone via DateTimeZone instance or string
$dt->tz = new DateTimeZone('Europe/London');
$dt->tz = 'Europe/London';

// The ->timezone is also available for backward compatibility but
// it will be overridden by native php DateTime class as soon as
// the object is dump (passed foreach, serialize, var_export, clone, etc.)
// making the Carbon setter inefficient, if it happen, you can cleanup
// those overridden properties by calling ->cleanupDumpProperties() on
// the instance, but we rather recommend to simply use ->tz instead
// of ->timezone everywhere.

// verbose way:
$dt->setYear(2001);
echo $dt->year;      // 2001
echo "\n";

// set/get method:
$dt->year(2002);
echo $dt->year();    // 0000-05-22 03:32:05
echo "\n";

// dynamic way:
$dt->set('year', 2003);
echo $dt->get('year'); // 2003
echo "\n";

// these methods exist for every units even for calculated properties such as:
echo $dt->dayOfYear(35)->format('Y-m-d'); // 2003-02-04

Weeks

If you are familiar with momentjs, you will find all week methods working the same. Most of them have an iso{Method} variant. Week methods follow the rules of the current locale (for example with en_US, the default locale, the first day of the week is Sunday, and the first week of the year is the one that contains January 1st). ISO methods follow the ISO 8601 norm, meaning weeks start with Monday and the first week of the year is the one containing January 4th.

$en = CarbonImmutable::now()->locale('en_US');
$ar = CarbonImmutable::now()->locale('ar');

var_dump($en->firstWeekDay);                           // int(0)
var_dump($en->lastWeekDay);                            // int(6)
var_dump($en->startOfWeek()->format('Y-m-d H:i'));     // string(16) "2025-06-29 00:00"
var_dump($en->endOfWeek()->format('Y-m-d H:i'));       // string(16) "2025-07-05 23:59"

echo "-----------\n";

// We still can force to use an other day as start/end of week
$start = $en->startOfWeek(Carbon::TUESDAY);
$end = $en->endOfWeek(Carbon::MONDAY);
var_dump($start->format('Y-m-d H:i'));                 // string(16) "2025-07-01 00:00"
var_dump($end->format('Y-m-d H:i'));                   // string(16) "2025-07-07 23:59"

echo "-----------\n";

var_dump($ar->firstWeekDay);                           // int(6)
var_dump($ar->lastWeekDay);                            // int(5)
var_dump($ar->startOfWeek()->format('Y-m-d H:i'));     // string(16) "2025-07-05 00:00"
var_dump($ar->endOfWeek()->format('Y-m-d H:i'));       // string(16) "2025-07-11 23:59"

$en = CarbonImmutable::parse('2015-02-05'); // use en_US as default locale

echo "-----------\n";

var_dump($en->weeksInYear());                          // int(52)
var_dump($en->isoWeeksInYear());                       // int(53)

$en = CarbonImmutable::parse('2017-02-05');

echo "-----------\n";

var_dump($en->week());                                 // int(6)
var_dump($en->isoWeek());                              // int(5)
var_dump($en->week(1)->format('Y-m-d H:i'));           // string(16) "2017-01-01 00:00"
var_dump($en->isoWeek(1)->format('Y-m-d H:i'));        // string(16) "2017-01-08 00:00"

// weekday/isoWeekday are meant to be used with days constants
var_dump($en->weekday());                              // int(0)
var_dump($en->isoWeekday());                           // int(7)
var_dump($en->weekday(CarbonInterface::WEDNESDAY)
    ->format('Y-m-d H:i'));                                                                               // string(16) "2017-02-01 00:00"
var_dump($en->isoWeekday(CarbonInterface::WEDNESDAY)
    ->format('Y-m-d H:i'));                                                                                  // string(16) "2017-02-01 00:00"

// getDaysFromStartOfWeek/setDaysFromStartOfWeek return and take a number of days
// taking the current locale into account
$date = CarbonImmutable::parse('2022-12-05')->locale('en_US');

var_dump($date->getDaysFromStartOfWeek());                     // int(1)

$date = CarbonImmutable::parse('2022-12-05')->locale('de_AT');

var_dump($date->getDaysFromStartOfWeek());                     // int(0)
var_dump($date->setDaysFromStartOfWeek(3)->format('Y-m-d'));   // string(10) "2022-12-08"

// Or specify explicitly the first day of week
var_dump($date->setDaysFromStartOfWeek(3, CarbonInterface::SUNDAY)->format('Y-m-d')); // string(10) "2022-12-07"

$en = CarbonImmutable::parse('2017-01-01');

echo "-----------\n";

var_dump($en->weekYear());                             // int(2017)
var_dump($en->isoWeekYear());                          // int(2016)
var_dump($en->weekYear(2016)->format('Y-m-d H:i'));    // string(16) "2016-01-03 00:00"
var_dump($en->isoWeekYear(2016)->format('Y-m-d H:i')); // string(16) "2017-01-01 00:00"
var_dump($en->weekYear(2015)->format('Y-m-d H:i'));    // string(16) "2015-01-04 00:00"
var_dump($en->isoWeekYear(2015)->format('Y-m-d H:i')); // string(16) "2015-12-27 00:00"

// Note you still can force first day of week and year to use:
$en = CarbonImmutable::parse('2017-01-01');

echo "-----------\n";

var_dump($en->weeksInYear(null, 6, 12));               // int(52)
var_dump($en->isoWeeksInYear(null, 6, 12));            // int(52)
var_dump($en->week(null, 6, 12));                      // int(52)
var_dump($en->isoWeek(null, 6, 12));                   // int(52)
var_dump($en->weekYear(null, 6, 12));                  // int(2016)
var_dump($en->isoWeekYear(null, 6, 12));               // int(2016)
var_dump($en->weekYear(2016, 6, 12)->format('Y-m-d H:i')); // string(16) "2017-01-01 00:00"
var_dump($en->isoWeekYear(2016, 6, 12)->format('Y-m-d H:i')); // string(16) "2017-01-01 00:00"
// Then you can see using a method or its ISO variant return identical results

Fluent Setters

You can call any base unit as a setter or some grouped setters:

$dt = Carbon::now();

$dt->year(1975)->month(5)->day(21)->hour(22)->minute(32)->second(5)->toDateTimeString();
$dt->setDate(1975, 5, 21)->setTime(22, 32, 5)->toDateTimeString();
$dt->setDate(1975, 5, 21)->setTimeFromTimeString('22:32:05')->toDateTimeString();
$dt->setDateTime(1975, 5, 21, 22, 32, 5)->toDateTimeString();

// All allow microsecond as optional argument
$dt->year(1975)->month(5)->day(21)->hour(22)->minute(32)->second(5)->microsecond(123456)->toDateTimeString();
$dt->setDate(1975, 5, 21)->setTime(22, 32, 5, 123456)->toDateTimeString();
$dt->setDate(1975, 5, 21)->setTimeFromTimeString('22:32:05.123456')->toDateTimeString();
$dt->setDateTime(1975, 5, 21, 22, 32, 5, 123456)->toDateTimeString();

$dt->timestamp(169957925); // Note: timestamps are UTC but do not change the date timezone

$dt->timezone('Europe/London')->tz('America/Toronto')->setTimezone('America/Vancouver');

You also can set date and time separately from other DateTime/Carbon objects:

$source1 = new Carbon('2010-05-16 22:40:10.1');

$dt = new Carbon('2001-01-01 01:01:01.2');
$dt->setTimeFrom($source1);

echo $dt; // 2001-01-01 22:40:10

$source2 = new DateTime('2013-09-01 09:22:56.2');

$dt->setDateFrom($source2);

echo $dt; // 2013-09-01 22:40:10

$dt->setDateTimeFrom($source2); // set date and time including microseconds
// bot not settings as locale, timezone, options.

String Formatting

All of the available toXXXString() methods rely on the base class method DateTime::format(). You'll notice the __toString() method is defined which allows a Carbon instance to be printed as a pretty date time string when used in a string context.

$dt = Carbon::create(1975, 12, 25, 14, 15, 16);

var_dump($dt->toDateTimeString() == $dt);          // bool(true) => uses __toString()
echo $dt->toDateString();                          // 1975-12-25
echo $dt->toFormattedDateString();                 // Dec 25, 1975
echo $dt->toFormattedDayDateString();              // Thu, Dec 25, 1975
echo $dt->toTimeString();                          // 14:15:16
echo $dt->toDateTimeString();                      // 1975-12-25 14:15:16
echo $dt->toDayDateTimeString();                   // Thu, Dec 25, 1975 2:15 PM

// ... of course format() is still available
echo $dt->format('l jS \\of F Y h:i:s A');         // Thursday 25th of December 1975 02:15:16 PM

// The reverse hasFormat method allows you to test if a string looks like a given format
var_dump(Carbon::hasFormat('Thursday 25th December 1975 02:15:16 PM', 'l jS F Y h:i:s A')); // bool(true)

You can also set the default __toString() format (which defaults to Y-m-d H:i:s) that's used when type juggling occurs.

echo $dt;                                          // 1975-12-25 14:15:16
echo "\n";
$dt->settings([
    'toStringFormat' => 'jS \o\f F, Y g:i:s a',
]);
echo $dt;                                          // 25th of December, 1975 2:15:16 pm

// As any setting, you can get the current value for a given date using:
var_dump($dt->getSettings());
/*
array(2) {
  ["toStringFormat"]=>
  string(20) "jS \o\f F, Y g:i:s a"
  ["timezone"]=>
  string(3) "UTC"
}*/

As part of the settings 'toStringFormat' can be used in factories too. It also may be a closure, so you can run any code on string cast.

If you use Carbon 1 or want to apply it globally as default format, you can use:

$dt = Carbon::create(1975, 12, 25, 14, 15, 16);
Carbon::setToStringFormat('jS \o\f F, Y g:i:s a');
echo $dt;                                          // 25th of December, 1975 2:15:16 pm
echo "\n";
Carbon::resetToStringFormat();
echo $dt;                                          // 1975-12-25 14:15:16

Note: For localization support see the Localization section.

Common Formats

The following are wrappers for the common formats provided in the DateTime class.

$dt = Carbon::createFromFormat('Y-m-d H:i:s.u', '2019-02-01 03:45:27.612584');

// $dt->toAtomString() is the same as $dt->format(DateTime::ATOM);
echo $dt->toAtomString();           // 2019-02-01T03:45:27+00:00
echo $dt->toCookieString();         // Friday, 01-Feb-2019 03:45:27 UTC

echo $dt->toIso8601String();        // 2019-02-01T03:45:27+00:00
// Be aware we chose to use the full-extended format of the ISO 8601 norm
// Natively, DateTime::ISO8601 format is not compatible with ISO-8601 as it
// is explained here in the PHP documentation:
// https://php.net/manual/class.datetime.php#datetime.constants.iso8601
// We consider it as a PHP mistake and chose not to provide method for this
// format, but you still can use it this way:
echo $dt->format(DateTime::ISO8601); // 2019-02-01T03:45:27+0000

echo $dt->toISOString();            // 2019-02-01T03:45:27.612584Z
echo $dt->toJSON();                 // 2019-02-01T03:45:27.612584Z

echo $dt->toIso8601ZuluString();    // 2019-02-01T03:45:27Z
echo $dt->toDateTimeLocalString();  // 2019-02-01T03:45:27
echo $dt->toRfc822String();         // Fri, 01 Feb 19 03:45:27 +0000
echo $dt->toRfc850String();         // Friday, 01-Feb-19 03:45:27 UTC
echo $dt->toRfc1036String();        // Fri, 01 Feb 19 03:45:27 +0000
echo $dt->toRfc1123String();        // Fri, 01 Feb 2019 03:45:27 +0000
echo $dt->toRfc2822String();        // Fri, 01 Feb 2019 03:45:27 +0000
echo $dt->toRfc3339String();        // 2019-02-01T03:45:27+00:00
echo $dt->toRfc7231String();        // Fri, 01 Feb 2019 03:45:27 GMT
echo $dt->toRssString();            // Fri, 01 Feb 2019 03:45:27 +0000
echo $dt->toW3cString();            // 2019-02-01T03:45:27+00:00

Conversion

$dt = Carbon::createFromFormat('Y-m-d H:i:s.u', '2019-02-01 03:45:27.612584');

var_dump($dt->toArray());
/*
array(12) {
  ["year"]=>
  int(2019)
  ["month"]=>
  int(2)
  ["day"]=>
  int(1)
  ["dayOfWeek"]=>
  int(5)
  ["dayOfYear"]=>
  int(32)
  ["hour"]=>
  int(3)
  ["minute"]=>
  int(45)
  ["second"]=>
  int(27)
  ["micro"]=>
  int(612584)
  ["timestamp"]=>
  int(1548992727)
  ["formatted"]=>
  string(19) "2019-02-01 03:45:27"
  ["timezone"]=>
  object(Carbon\CarbonTimeZone)#567 (3) {
    ["clock":"Carbon\CarbonTimeZone":private]=>
    NULL
    ["timezone_type"]=>
    int(3)
    ["timezone"]=>
    string(3) "UTC"
  }
}
*/

var_dump($dt->toObject());
/*
object(stdClass)#567 (12) {
  ["year"]=>
  int(2019)
  ["month"]=>
  int(2)
  ["day"]=>
  int(1)
  ["dayOfWeek"]=>
  int(5)
  ["dayOfYear"]=>
  int(32)
  ["hour"]=>
  int(3)
  ["minute"]=>
  int(45)
  ["second"]=>
  int(27)
  ["micro"]=>
  int(612584)
  ["timestamp"]=>
  int(1548992727)
  ["formatted"]=>
  string(19) "2019-02-01 03:45:27"
  ["timezone"]=>
  object(Carbon\CarbonTimeZone)#650 (3) {
    ["clock":"Carbon\CarbonTimeZone":private]=>
    NULL
    ["timezone_type"]=>
    int(3)
    ["timezone"]=>
    string(3) "UTC"
  }
}
*/

var_dump($dt->toDate()); // Same as $dt->toDateTime()
/*
object(DateTime)#567 (3) {
  ["date"]=>
  string(26) "2019-02-01 03:45:27.612584"
  ["timezone_type"]=>
  int(3)
  ["timezone"]=>
  string(3) "UTC"
}
*/

// Note than both Carbon and CarbonImmutable can be cast
// to both DateTime and DateTimeImmutable
var_dump($dt->toDateTimeImmutable());
/*
object(DateTimeImmutable)#1590 (3) {
  ["date"]=>
  string(26) "2019-02-01 03:45:27.612584"
  ["timezone_type"]=>
  int(3)
  ["timezone"]=>
  string(3) "UTC"
}
*/

class MySubClass extends Carbon {}
// MySubClass can be any class implementing CarbonInterface or a public static instance() method.

$copy = $dt->cast(MySubClass::class);
// Since 2.23.0, cast() can also take as argument any class that extend DateTime or DateTimeImmutable

echo get_class($copy).': '.$copy; // Same as MySubClass::instance($dt)
/*
MySubClass: 2019-02-01 03:45:27
*/

You can use the method carbonize to transform many things into a Carbon instance based on a given source instance used as reference on need. It returns a new instance.

$dt = Carbon::createFromFormat('Y-m-d H:i:s.u', '2019-02-01 03:45:27.612584', 'Europe/Paris');

// Can take a date string and will apply the timezone from reference object
var_dump($dt->carbonize('2019-03-21'));
/*
array(2) {
  ["date"]=>
  string(26) "2019-03-21 00:00:00.000000"
  ["timezone"]=>
  string(12) "Europe/Paris"
}
*/

// If you pass a DatePeriod or CarbonPeriod, it will copy the period start
var_dump($dt->carbonize(CarbonPeriod::create('2019-12-10', '2020-01-05')));
/*
array(2) {
  ["date"]=>
  string(26) "2019-12-10 00:00:00.000000"
  ["timezone"]=>
  string(3) "UTC"
}
*/

// If you pass a DateInterval or CarbonInterval, it will add the interval to
// the reference object
var_dump($dt->carbonize(CarbonInterval::days(3)));
/*
array(2) {
  ["date"]=>
  string(26) "2019-02-04 03:45:27.612584"
  ["timezone"]=>
  string(12) "Europe/Paris"
}
*/

Comparison

Simple comparison is offered up via the following functions. Remember that the comparison is done in the UTC timezone so things aren't always as they seem.

echo Carbon::now()->tzName;                        // UTC
$first = Carbon::create(2012, 9, 5, 23, 26, 11);
$second = Carbon::create(2012, 9, 5, 20, 26, 11, 'America/Vancouver');

echo $first->toDateTimeString();                   // 2012-09-05 23:26:11
echo $first->tzName;                               // UTC
echo $second->toDateTimeString();                  // 2012-09-05 20:26:11
echo $second->tzName;                              // America/Vancouver

var_dump($first->equalTo($second));                // bool(false)
// equalTo is also available on CarbonInterval and CarbonPeriod
var_dump($first->notEqualTo($second));             // bool(true)
// notEqualTo is also available on CarbonInterval and CarbonPeriod
var_dump($first->greaterThan($second));            // bool(false)
// greaterThan is also available on CarbonInterval
var_dump($first->greaterThanOrEqualTo($second));   // bool(false)
// greaterThanOrEqualTo is also available on CarbonInterval
var_dump($first->lessThan($second));               // bool(true)
// lessThan is also available on CarbonInterval
var_dump($first->lessThanOrEqualTo($second));      // bool(true)
// lessThanOrEqualTo is also available on CarbonInterval

$first->setDateTime(2012, 1, 1, 0, 0, 0);
$second->setDateTime(2012, 1, 1, 0, 0, 0);         // Remember tz is 'America/Vancouver'

var_dump($first->equalTo($second));                // bool(false)
var_dump($first->notEqualTo($second));             // bool(true)
var_dump($first->greaterThan($second));            // bool(false)
var_dump($first->greaterThanOrEqualTo($second));   // bool(false)
var_dump($first->lessThan($second));               // bool(true)
var_dump($first->lessThanOrEqualTo($second));      // bool(true)

// All have short hand aliases and PHP equivalent code:

var_dump($first->eq($second));                     // bool(false)
var_dump($first->equalTo($second));                // bool(false)
var_dump($first == $second);                       // bool(false)

var_dump($first->ne($second));                     // bool(true)
var_dump($first->notEqualTo($second));             // bool(true)
var_dump($first != $second);                       // bool(true)

var_dump($first->gt($second));                     // bool(false)
var_dump($first->greaterThan($second));            // bool(false)
var_dump($first->isAfter($second));                // bool(false)
var_dump($first > $second);                        // bool(false)

var_dump($first->gte($second));                    // bool(false)
var_dump($first->greaterThanOrEqualTo($second));   // bool(false)
var_dump($first >= $second);                       // bool(false)

var_dump($first->lt($second));                     // bool(true)
var_dump($first->lessThan($second));               // bool(true)
var_dump($first->isBefore($second));               // bool(true)
var_dump($first < $second);                        // bool(true)

var_dump($first->lte($second));                    // bool(true)
var_dump($first->lessThanOrEqualTo($second));      // bool(true)
var_dump($first <= $second);                       // bool(true)

Those methods use natural comparisons offered by PHP $date1 == $date2 so all of them will ignore milli/micro-seconds before PHP 7.1, then take them into account starting with 7.1.

To determine if the current instance is between two other instances you can use the aptly named between() method (or isBetween() alias). The third parameter indicates if an equal to comparison should be done. The default is true which determines if its between or equal to the boundaries.

$first = Carbon::create(2012, 9, 5, 1);
$second = Carbon::create(2012, 9, 5, 5);
var_dump(Carbon::create(2012, 9, 5, 3)->between($first, $second));          // bool(true)
var_dump(Carbon::create(2012, 9, 5, 5)->between($first, $second));          // bool(true)
var_dump(Carbon::create(2012, 9, 5, 5)->between($first, $second, false));   // bool(false)
var_dump(Carbon::create(2012, 9, 5, 5)->isBetween($first, $second, false)); // bool(false)
// Rather than passing false as a third argument, you can use betweenIncluded and betweenExcluded
var_dump(Carbon::create(2012, 9, 5, 5)->betweenIncluded($first, $second));  // bool(true)
var_dump(Carbon::create(2012, 9, 5, 5)->betweenExcluded($first, $second));  // bool(false)
// All those methods are also available on CarbonInterval

Woah! Did you forget min() and max() ? Nope. That is covered as well by the suitably named min() and max() methods or minimum() and maximum() aliases. As usual the default parameter is now if null is specified.

$dt1 = Carbon::createMidnightDate(2012, 1, 1);
$dt2 = Carbon::createMidnightDate(2014, 1, 30);
echo $dt1->min($dt2);                              // 2012-01-01 00:00:00
echo $dt1->minimum($dt2);                          // 2012-01-01 00:00:00
// Also works with string
echo $dt1->minimum('2014-01-30');                  // 2012-01-01 00:00:00

$dt1 = Carbon::createMidnightDate(2012, 1, 1);
$dt2 = Carbon::createMidnightDate(2014, 1, 30);
echo $dt1->max($dt2);                              // 2014-01-30 00:00:00
echo $dt1->maximum($dt2);                          // 2014-01-30 00:00:00

// now is the default param
$dt1 = Carbon::createMidnightDate(2000, 1, 1);
echo $dt1->max();                                  // 2025-07-05 06:05:56
echo $dt1->maximum();                              // 2025-07-05 06:05:56

// Remember min and max PHP native function work fine with dates too:
echo max(Carbon::create('2002-03-15'), Carbon::create('2003-01-07'), Carbon::create('2002-08-25')); // 2003-01-07 00:00:00
echo min(Carbon::create('2002-03-15'), Carbon::create('2003-01-07'), Carbon::create('2002-08-25')); // 2002-03-15 00:00:00
// This way you can pass as many dates as you want and get no ambiguities about parameters order

$dt1 = Carbon::createMidnightDate(2010, 4, 1);
$dt2 = Carbon::createMidnightDate(2010, 3, 28);
$dt3 = Carbon::createMidnightDate(2010, 4, 16);

// returns the closest of two date (no matter before or after)
echo $dt1->closest($dt2, $dt3);                    // 2010-03-28 00:00:00
echo $dt2->closest($dt1, $dt3);                    // 2010-04-01 00:00:00
echo $dt3->closest($dt2, $dt1);                    // 2010-04-01 00:00:00

// returns the farthest of two date (no matter before or after)
echo $dt1->farthest($dt2, $dt3);                   // 2010-04-16 00:00:00
echo $dt2->farthest($dt1, $dt3);                   // 2010-04-16 00:00:00
echo $dt3->farthest($dt2, $dt1);                   // 2010-03-28 00:00:00

To handle the most used cases there are some simple helper functions that hopefully are obvious from their names. For the methods that compare to now() (ex. isToday()) in some manner, the now() is created in the same timezone as the instance.

$dt = Carbon::now();
$dt2 = Carbon::createFromDate(1987, 4, 23);

$dt->isSameAs('w', $dt2); // w is the date of the week, so this will return true if $dt and $dt2
                          // the same day of week (both monday or both sunday, etc.)
                          // you can use any format and combine as much as you want.
$dt->isFuture();
$dt->isNowOrFuture();
$dt->isPast();
$dt->isNowOrPast();

$dt->isSameYear($dt2);
$dt->isCurrentYear();
$dt->isNextYear();
$dt->isLastYear();
$dt->isLongIsoYear(); // see https://en.wikipedia.org/wiki/ISO_8601#Week_dates
Carbon::create(2015)->isLongYear(); // isLongIsoYear() check a given date,
    // while isLongYear() will ignore month/day and just check a given year number
$dt->isLeapYear();

$dt->isSameQuarter($dt2); // same quarter of the same year of the given date
$dt->isSameQuarter($dt2, false); // same quarter (3 months) no matter the year of the given date
$dt->isCurrentQuarter();
$dt->isNextQuarter(); // date is in the next quarter
$dt->isLastQuarter(); // in previous quarter

$dt->isSameMonth($dt2); // same month of the same year of the given date
$dt->isSameMonth($dt2, false); // same month no matter the year of the given date
$dt->isCurrentMonth();
$dt->isNextMonth();
$dt->isLastMonth();

$dt->isWeekday();
$dt->isWeekend();
$dt->isMonday();
$dt->isTuesday();
$dt->isWednesday();
$dt->isThursday();
$dt->isFriday();
$dt->isSaturday();
$dt->isSunday();
$dt->isDayOfWeek(Carbon::SATURDAY); // is a saturday
$dt->isLastOfMonth(); // is the last day of the month

$dt->is('Sunday');
$dt->is('June');
$dt->is('2019');
$dt->is('12:23');
$dt->is('2 June 2019');
$dt->is('06-02');

$dt->isSameDay($dt2); // Same day of same month of same year
$dt->isCurrentDay();
$dt->isYesterday();
$dt->isToday();
$dt->isTomorrow();
$dt->isNextWeek();
$dt->isLastWeek();

$dt->isSameHour($dt2);
$dt->isCurrentHour();
$dt->isSameMinute($dt2);
$dt->isCurrentMinute();
$dt->isSameSecond($dt2);
$dt->isCurrentSecond();

$dt->isStartOfDay(); // check if hour is 00:00:00
$dt->isMidnight(); // check if hour is 00:00:00 (isStartOfDay alias)
$dt->isEndOfDay(); // check if hour is 23:59:59
$dt->isMidday(); // check if hour is 12:00:00 (or other midday hour set with Carbon::setMidDayAt())
$born = Carbon::createFromDate(1987, 4, 23);
$noCake = Carbon::createFromDate(2014, 9, 26);
$yesCake = Carbon::createFromDate(2014, 4, 23);
$overTheHill = Carbon::now()->subYears(50);
var_dump($born->isBirthday($noCake));              // bool(false)
var_dump($born->isBirthday($yesCake));             // bool(true)
var_dump($overTheHill->isBirthday());              // bool(true) -> default compare it to today!

// isStartOfX, isEndOfX, isCurrentX, isSameX, isNextX and isLastX are available for each unit

The methods isStartOfMillisecond, isEndOfMillisecond, isStartOfSecond, isEndOfSecond, isStartOfMinute, isEndOfMinute, isStartOfHour, isEndOfHour, isStartOfDay and isEndOfDay will use 1 microsecond as the default interval to be considered as the start/end, which means isEndOfDay returns true only for 23:59:59.999999, false for 23:59:59.999998.

The methods isStartOfWeek, isEndOfWeek, isStartOfMonth, isEndOfMonth, isStartOfQuarter, isEndOfQuarter, isStartOfYear, isEndOfYear, isStartOfDecade, isEndOfDecade, isStartOfCentury, isEndOfCentury, isStartOfMillennium and isEndOfMillennium will use 1 day as the default interval to be considered as the start/end. isStartOfUnit

But you can customize this interval: $date->isStartOfDay(interval: '4 hours') (true if the current time is >= 00:00:00.000000 and <= 03:59:59.999999).

$date->isEndOfCentury(interval: Unit::Year) (true if the current year is the last one of a century, i.e. ends with 00).

isStartOfUnit and isEndOfUnit allow this check with dynamic unit: $date->isStartOfUnit(Unit::Year, interval: '1 month'), $date->isStartOfUnit(Unit::Week, Unit::Hour)

Addition and Subtraction

The default DateTime provides a couple of different methods for easily adding and subtracting time. There is modify(), add() and sub(). change() is an enhanced version of modify() that can take magical date/time format string, 'last day of next month', that it parses and applies the modification while add() and sub() can take the same the same kind of string, intervals (DateInterval or CarbonInterval) or count+unit parameters. But you can still access the native methods of DateTime class using rawAdd() and rawSub().

$dt = Carbon::create(2012, 1, 31, 0);

echo $dt->toDateTimeString();            // 2012-01-31 00:00:00

echo $dt->addCenturies(5);               // 2512-01-31 00:00:00
echo $dt->addCentury();                  // 2612-01-31 00:00:00
echo $dt->subCentury();                  // 2512-01-31 00:00:00
echo $dt->subCenturies(5);               // 2012-01-31 00:00:00

echo $dt->addYears(5);                   // 2017-01-31 00:00:00
echo $dt->addYear();                     // 2018-01-31 00:00:00
echo $dt->subYear();                     // 2017-01-31 00:00:00
echo $dt->subYears(5);                   // 2012-01-31 00:00:00

echo $dt->addQuarters(2);                // 2012-07-31 00:00:00
echo $dt->addQuarter();                  // 2012-10-31 00:00:00
echo $dt->subQuarter();                  // 2012-07-31 00:00:00
echo $dt->subQuarters(2);                // 2012-01-31 00:00:00

echo $dt->addMonths(60);                 // 2017-01-31 00:00:00
echo $dt->addMonth();                    // 2017-03-03 00:00:00 equivalent of $dt->month($dt->month + 1); so it wraps
echo $dt->subMonth();                    // 2017-02-03 00:00:00
echo $dt->subMonths(60);                 // 2012-02-03 00:00:00

echo $dt->addDays(29);                   // 2012-03-03 00:00:00
echo $dt->addDay();                      // 2012-03-04 00:00:00
echo $dt->subDay();                      // 2012-03-03 00:00:00
echo $dt->subDays(29);                   // 2012-02-03 00:00:00

echo $dt->addWeekdays(4);                // 2012-02-09 00:00:00
echo $dt->addWeekday();                  // 2012-02-10 00:00:00
echo $dt->subWeekday();                  // 2012-02-09 00:00:00
echo $dt->subWeekdays(4);                // 2012-02-03 00:00:00

echo $dt->addWeeks(3);                   // 2012-02-24 00:00:00
echo $dt->addWeek();                     // 2012-03-02 00:00:00
echo $dt->subWeek();                     // 2012-02-24 00:00:00
echo $dt->subWeeks(3);                   // 2012-02-03 00:00:00

echo $dt->addHours(24);                  // 2012-02-04 00:00:00
echo $dt->addHour();                     // 2012-02-04 01:00:00
echo $dt->subHour();                     // 2012-02-04 00:00:00
echo $dt->subHours(24);                  // 2012-02-03 00:00:00

echo $dt->addMinutes(61);                // 2012-02-03 01:01:00
echo $dt->addMinute();                   // 2012-02-03 01:02:00
echo $dt->subMinute();                   // 2012-02-03 01:01:00
echo $dt->subMinutes(61);                // 2012-02-03 00:00:00

echo $dt->addSeconds(61);                // 2012-02-03 00:01:01
echo $dt->addSecond();                   // 2012-02-03 00:01:02
echo $dt->subSecond();                   // 2012-02-03 00:01:01
echo $dt->subSeconds(61);                // 2012-02-03 00:00:00

echo $dt->addMilliseconds(61);           // 2012-02-03 00:00:00
echo $dt->addMillisecond();              // 2012-02-03 00:00:00
echo $dt->subMillisecond();              // 2012-02-03 00:00:00
echo $dt->subMillisecond(61);            // 2012-02-03 00:00:00

echo $dt->addMicroseconds(61);           // 2012-02-03 00:00:00
echo $dt->addMicrosecond();              // 2012-02-03 00:00:00
echo $dt->subMicrosecond();              // 2012-02-03 00:00:00
echo $dt->subMicroseconds(61);           // 2012-02-03 00:00:00

// and so on for any unit: millenium, century, decade, year, quarter, month, week, day, weekday,
// hour, minute, second, microsecond.

// Generic methods add/sub (or subtract alias) can take many different arguments:
echo $dt->add(61, 'seconds');                      // 2012-02-03 00:01:01
echo $dt->sub('1 day');                            // 2012-02-02 00:01:01
echo $dt->add(CarbonInterval::months(2));          // 2012-04-02 00:01:01
echo $dt->subtract(new DateInterval('PT1H'));      // 2012-04-01 23:01:01

For fun you can also pass negative values to addXXX(), in fact that's how subXXX() is implemented.

P.S. Don't worry if you forget and use addDay(5) or subYear(3), I have your back ;)

By default, Carbon relies on the underlying parent class PHP DateTime behavior. As a result adding or subtracting months can overflow, example:

$dt = CarbonImmutable::create(2017, 1, 31, 0);

echo $dt->addMonth();                    // 2017-03-03 00:00:00
echo "\n";
echo $dt->subMonths(2);                  // 2016-12-01 00:00:00

Since Carbon 2, you can set a local overflow behavior for each instance:

$dt = CarbonImmutable::create(2017, 1, 31, 0);
$dt->settings([
    'monthOverflow' => false,
]);

echo $dt->addMonth();                    // 2017-02-28 00:00:00
echo "\n";
echo $dt->subMonths(2);                  // 2016-11-30 00:00:00

This will apply for methods addMonth(s), subMonth(s), add($x, 'month'), sub($x, 'month') and equivalent quarter methods. But it won't apply for intervals objects or strings like add(CarbonInterval::month()) or add('1 month').

Static helpers exist but are deprecated. If you're sure to need to apply global setting or work with version 1 of Carbon, check the overflow static helpers section

Carbon::useMonthsOverflow(false);

$dt = Carbon::createMidnightDate(2017, 1, 31);

echo $dt->copy()->addMonth();            // 2017-02-28 00:00:00
echo "\n";
echo $dt->copy()->subMonths(2);          // 2016-11-30 00:00:00

// Call the method with true to allow overflow again
Carbon::resetMonthsOverflow(); // same as Carbon::useMonthsOverflow(true);

Carbon::useMonthsOverflow(false);

$dt = Carbon::createMidnightDate(2017, 1, 31);

echo $dt->copy()->addMonthWithOverflow();          // 2017-03-03 00:00:00
// plural addMonthsWithOverflow() method is also available
echo $dt->copy()->subMonthsWithOverflow(2);        // 2016-12-01 00:00:00
// singular subMonthWithOverflow() method is also available
echo $dt->copy()->addMonthNoOverflow();            // 2017-02-28 00:00:00
// plural addMonthsNoOverflow() method is also available
echo $dt->copy()->subMonthsNoOverflow(2);          // 2016-11-30 00:00:00
// singular subMonthNoOverflow() method is also available

echo $dt->copy()->addMonth();                      // 2017-02-28 00:00:00
echo $dt->copy()->subMonths(2);                    // 2016-11-30 00:00:00

Carbon::useMonthsOverflow(true);

$dt = Carbon::createMidnightDate(2017, 1, 31);

echo $dt->copy()->addMonthWithOverflow();          // 2017-03-03 00:00:00
echo $dt->copy()->subMonthsWithOverflow(2);        // 2016-12-01 00:00:00
echo $dt->copy()->addMonthNoOverflow();            // 2017-02-28 00:00:00
echo $dt->copy()->subMonthsNoOverflow(2);          // 2016-11-30 00:00:00

echo $dt->copy()->addMonth();                      // 2017-03-03 00:00:00
echo $dt->copy()->subMonths(2);                    // 2016-12-01 00:00:00

Carbon::resetMonthsOverflow();

Carbon::useYearsOverflow(false);

$dt = Carbon::createMidnightDate(2020, 2, 29);

var_dump(Carbon::shouldOverflowYears());           // bool(false)

echo $dt->copy()->addYearWithOverflow();           // 2021-03-01 00:00:00
// plural addYearsWithOverflow() method is also available
echo $dt->copy()->subYearsWithOverflow(2);         // 2018-03-01 00:00:00
// singular subYearWithOverflow() method is also available
echo $dt->copy()->addYearNoOverflow();             // 2021-02-28 00:00:00
// plural addYearsNoOverflow() method is also available
echo $dt->copy()->subYearsNoOverflow(2);           // 2018-02-28 00:00:00
// singular subYearNoOverflow() method is also available

echo $dt->copy()->addYear();                       // 2021-02-28 00:00:00
echo $dt->copy()->subYears(2);                     // 2018-02-28 00:00:00

Carbon::useYearsOverflow(true);

$dt = Carbon::createMidnightDate(2020, 2, 29);

var_dump(Carbon::shouldOverflowYears());           // bool(true)

echo $dt->copy()->addYearWithOverflow();           // 2021-03-01 00:00:00
echo $dt->copy()->subYearsWithOverflow(2);         // 2018-03-01 00:00:00
echo $dt->copy()->addYearNoOverflow();             // 2021-02-28 00:00:00
echo $dt->copy()->subYearsNoOverflow(2);           // 2018-02-28 00:00:00

echo $dt->copy()->addYear();                       // 2021-03-01 00:00:00
echo $dt->copy()->subYears(2);                     // 2018-03-01 00:00:00

Carbon::resetYearsOverflow();

You also can use ->addMonthsNoOverflow, ->subMonthsNoOverflow, ->addMonthsWithOverflow and ->subMonthsWithOverflow (or the singular methods with no s to "month") to explicitly add/sub months with or without overflow no matter the current mode and the same for any bigger unit (quarter, year, decade, century, millennium).

$dt = Carbon::createMidnightDate(2017, 1, 31)->settings([
    'monthOverflow' => false,
]);

echo $dt->copy()->addMonthWithOverflow();          // 2017-03-03 00:00:00
// plural addMonthsWithOverflow() method is also available
echo $dt->copy()->subMonthsWithOverflow(2);        // 2016-12-01 00:00:00
// singular subMonthWithOverflow() method is also available
echo $dt->copy()->addMonthNoOverflow();            // 2017-02-28 00:00:00
// plural addMonthsNoOverflow() method is also available
echo $dt->copy()->subMonthsNoOverflow(2);          // 2016-11-30 00:00:00
// singular subMonthNoOverflow() method is also available

echo $dt->copy()->addMonth();                      // 2017-02-28 00:00:00
echo $dt->copy()->subMonths(2);                    // 2016-11-30 00:00:00

$dt = Carbon::createMidnightDate(2017, 1, 31)->settings([
    'monthOverflow' => true,
]);

echo $dt->copy()->addMonthWithOverflow();          // 2017-03-03 00:00:00
echo $dt->copy()->subMonthsWithOverflow(2);        // 2016-12-01 00:00:00
echo $dt->copy()->addMonthNoOverflow();            // 2017-02-28 00:00:00
echo $dt->copy()->subMonthsNoOverflow(2);          // 2016-11-30 00:00:00

echo $dt->copy()->addMonth();                      // 2017-03-03 00:00:00
echo $dt->copy()->subMonths(2);                    // 2016-12-01 00:00:00

The same is available for years.

You also can control overflow for any unit when working with unknown inputs:

$dt = CarbonImmutable::create(2018, 8, 30, 12, 00, 00);

// Add hours without overflowing day
echo $dt->addUnitNoOverflow('hour', 7, 'day');     // 2018-08-30 19:00:00
echo "\n";
echo $dt->addUnitNoOverflow('hour', 14, 'day');    // 2018-08-30 23:59:59
echo "\n";
echo $dt->addUnitNoOverflow('hour', 48, 'day');    // 2018-08-30 23:59:59

echo "\n-------\n";

// Substract hours without overflowing day
echo $dt->subUnitNoOverflow('hour', 7, 'day');     // 2018-08-30 05:00:00
echo "\n";
echo $dt->subUnitNoOverflow('hour', 14, 'day');    // 2018-08-30 00:00:00
echo "\n";
echo $dt->subUnitNoOverflow('hour', 48, 'day');    // 2018-08-30 00:00:00

echo "\n-------\n";

// Set hours without overflowing day
echo $dt->setUnitNoOverflow('hour', -7, 'day');    // 2018-08-30 00:00:00
echo "\n";
echo $dt->setUnitNoOverflow('hour', 14, 'day');    // 2018-08-30 14:00:00
echo "\n";
echo $dt->setUnitNoOverflow('hour', 25, 'day');    // 2018-08-30 23:59:59

echo "\n-------\n";

// Adding hours without overflowing month
echo $dt->addUnitNoOverflow('hour', 7, 'month');   // 2018-08-30 19:00:00
echo "\n";
echo $dt->addUnitNoOverflow('hour', 14, 'month');  // 2018-08-31 02:00:00
echo "\n";
echo $dt->addUnitNoOverflow('hour', 48, 'month');  // 2018-08-31 23:59:59

Any modifiable unit can be passed as argument of those methods:

$units = [];
foreach (['millennium', 'century', 'decade', 'year', 'quarter', 'month', 'week', 'weekday', 'day', 'hour', 'minute', 'second', 'millisecond', 'microsecond'] as $unit) {
    $units[$unit] = Carbon::isModifiableUnit($unit);
}

echo json_encode($units, JSON_PRETTY_PRINT);
/* {
    "millennium": true,
    "century": true,
    "decade": true,
    "year": true,
    "quarter": true,
    "month": true,
    "week": true,
    "weekday": true,
    "day": true,
    "hour": true,
    "minute": true,
    "second": true,
    "millisecond": true,
    "microsecond": true
} */

Difference

Carbon diff() and diffAsCarbonInterval() methods return a CarbonInterval (since Carbon v3, while it returned DateInterval in the previous versions).

Check CarbonInterval chapter for more information.

We also provide diffAsDateInterval() act like diff() but returns a DateInterval instance.

Carbon add diff methods for each unit too, such as diffInYears(), diffInMonths() and so on. diffAsCarbonInterval() and diffIn*() (and floatDiffIn*() for versions < 3 when diffIn*() methods returned integer values, since Carbon 3, they are deprecated as diffIn*() already return floating number, and integer values from it can easily be obtained with an explicit cast (int)).

diffInUnit() allow to get a diff for a unit calculated dynamically: ->diffInUnit($unit, $date, $absolute)

All can take 2 optional arguments: date to compare with (if missing, now is used instead), and an absolute boolean option (false by default), it returns negative value when the instance the method is called on is greater than the compared date (first argument or now). If set to true, that makes the method return an absolute value no matter which date is greater than the other.

echo Carbon::now('America/Vancouver')->diffInSeconds(Carbon::now('Europe/London')); // 4.0E-6

$dtOttawa = Carbon::createMidnightDate(2000, 1, 1, 'America/Toronto');
$dtVancouver = Carbon::createMidnightDate(2000, 1, 1, 'America/Vancouver');
echo $dtOttawa->diffInHours($dtVancouver);                             // 3
echo $dtVancouver->diffInHours($dtOttawa);                             // -3

echo $dtOttawa->diffInHours($dtVancouver, false);                      // 3
echo $dtVancouver->diffInHours($dtOttawa, false);                      // -3

$dt = Carbon::createMidnightDate(2012, 1, 31);
echo $dt->diffInDays($dt->copy()->addMonth());                         // 31
echo $dt->diffInDays($dt->copy()->subMonth(), false);                  // -31

$dt = Carbon::createMidnightDate(2012, 4, 30);
echo $dt->diffInDays($dt->copy()->addMonth());                         // 30
echo $dt->diffInDays($dt->copy()->addWeek());                          // 7

$dt = Carbon::createMidnightDate(2012, 1, 1);
echo $dt->diffInMinutes($dt->copy()->addSeconds(59));                  // 0.98333333333333
echo $dt->diffInMinutes($dt->copy()->addSeconds(60));                  // 1
echo $dt->diffInMinutes($dt->copy()->addSeconds(119));                 // 1.9833333333333
echo $dt->diffInMinutes($dt->copy()->addSeconds(120));                 // 2

echo $dt->addSeconds(120)->secondsSinceMidnight();                     // 120

$interval = $dt->diffAsCarbonInterval($dt->copy()->subYears(3), false);
// diffAsCarbonInterval use same arguments as diff($other, $absolute)
// (native method from \DateTime)
// except $absolute is true by default for diffAsCarbonInterval and false for diff
// $absolute parameter allow to get signed value if false, or always positive if true
echo ($interval->invert ? 'minus ' : 'plus ') . $interval->years;      // minus 3

These methods have int-truncated results. That means diffInMinutes returns 1 for any difference between 1 included and 2 excluded. But same methods are available for float results:

echo Carbon::parse('06:01:23.252987')->floatDiffInSeconds('06:02:34.321450');    // 71.068463
echo Carbon::parse('06:01:23')->floatDiffInMinutes('06:02:34');                  // 1.1833333333333
echo Carbon::parse('06:01:23')->floatDiffInHours('06:02:34');                    // 0.019722222222222
// Those methods are absolute by default but can return negative value
// setting the second argument to false when start date is greater than end date
echo Carbon::parse('12:01:23')->floatDiffInHours('06:02:34', false);             // -5.9802777777778
echo Carbon::parse('2000-01-01 12:00')->floatDiffInDays('2000-02-11 06:00');     // 40.75
echo Carbon::parse('2000-01-01')->floatDiffInWeeks('2000-02-11');                // 5.8571428571429
echo Carbon::parse('2000-01-15')->floatDiffInMonths('2000-02-24');               // 1.3103448275862
// floatDiffInMonths count as many full months as possible from the start date
// (for instance 31 days if the start is in January), then consider the number
// of days in the months for ending chunks to reach the end date.
// So the following result (ending with 24 march is different from previous one with 24 february):
echo Carbon::parse('2000-02-15 12:00')->floatDiffInMonths('2000-03-24 06:00');   // 1.2822580645161
// floatDiffInYears apply the same logic (and so different results with leap years)
echo Carbon::parse('2000-02-15 12:00')->floatDiffInYears('2010-03-24 06:00');    // 10.100684931507

⚠️ Important note about the daylight saving times (DST), by default PHP DateTime does not take DST into account, that means for example that a day with only 23 hours like March the 30th 2014 in London will be counted as 24 hours long.

⚠️ Be careful of floatDiffInMonths() which can gives you a lower result (number of months in A < number of months in B) for an interval having more days (number of days in A > number of days in B) due to the variable number of days in months (especially February). By default, we rely on the result of DateTime::diff which is sensitive to overflow. See issue #2264 for alternative calculations.

$date = new DateTime('2014-03-30 00:00:00', new DateTimeZone('Europe/London')); // DST off
echo $date->modify('+25 hours')->format('H:i');                   // 01:00 (DST on, 24 hours only have been actually added)

Carbon follow this behavior too for add/sub/diff seconds/minutes/hours. But we provide methods to works with real hours using timestamp:

$date = new Carbon('2014-03-30 00:00:00', 'Europe/London');       // DST off
echo $date->addRealHours(25)->format('H:i');                      // 02:00 (DST on)
echo $date->diffInRealHours('2014-03-30 00:00:00');               // -25
echo $date->diffInHours('2014-03-30 00:00:00');                   // -25
echo $date->diffInRealMinutes('2014-03-30 00:00:00');             // -1500
echo $date->diffInMinutes('2014-03-30 00:00:00');                 // -1500
echo $date->diffInRealSeconds('2014-03-30 00:00:00');             // -90000
echo $date->diffInSeconds('2014-03-30 00:00:00');                 // -90000
echo $date->diffInRealMilliseconds('2014-03-30 00:00:00');        // -90000000
echo $date->diffInMilliseconds('2014-03-30 00:00:00');            // -90000000
echo $date->diffInRealMicroseconds('2014-03-30 00:00:00');        // -90000000000
echo $date->diffInMicroseconds('2014-03-30 00:00:00');            // -90000000000
echo $date->subRealHours(25)->format('H:i');                      // 00:00 (DST off)

// with float diff:
$date = new Carbon('2019-10-27 00:00:00', 'Europe/Paris');
echo $date->floatDiffInRealHours('2019-10-28 12:30:00');          // 37.5
echo $date->floatDiffInHours('2019-10-28 12:30:00');              // 37.5
echo $date->floatDiffInRealMinutes('2019-10-28 12:00:30');        // 2220.5
echo $date->floatDiffInMinutes('2019-10-28 12:00:30');            // 2220.5
echo $date->floatDiffInRealSeconds('2019-10-28 12:00:00.5');      // 133200.5
echo $date->floatDiffInSeconds('2019-10-28 12:00:00.5');          // 133200.5
// above day unit, "real" will affect the decimal part based on hours and smaller units
echo $date->floatDiffInRealDays('2019-10-28 12:30:00');           // 1.5625
echo $date->floatDiffInDays('2019-10-28 12:30:00');               // 1.5208333333333
echo $date->floatDiffInRealWeeks('2019-10-28 12:30:00');          // 0.22321428571429
echo $date->floatDiffInWeeks('2019-10-28 12:30:00');              // 0.2172619047619
echo $date->floatDiffInRealMonths('2019-10-28 12:30:00');         // 0.050403225806452
echo $date->floatDiffInMonths('2019-10-28 12:30:00');             // 0.049059139784946
echo $date->floatDiffInRealYears('2019-10-28 12:30:00');          // 0.0042691256830601
echo $date->floatDiffInYears('2019-10-28 12:30:00');              // 0.0041552823315118

The same way you can use addRealX() and subRealX() on any unit.

There are also special filter functions diffInDaysFiltered(), diffInHoursFiltered() and diffFiltered(), to help you filter the difference by days, hours or a custom interval. For example to count the weekend days between two instances:

$dt = Carbon::create(2014, 1, 1);
$dt2 = Carbon::create(2014, 12, 31);
$daysForExtraCoding = $dt->diffInDaysFiltered(function(Carbon $date) {
   return $date->isWeekend();
}, $dt2);

echo $daysForExtraCoding;      // 104

$dt = Carbon::create(2014, 1, 1)->endOfDay();
$dt2 = $dt->copy()->startOfDay();
$littleHandRotations = $dt->diffFiltered(CarbonInterval::minute(), function(Carbon $date) {
   return $date->minute === 0;
}, $dt2, true); // true as last parameter returns absolute value

echo $littleHandRotations;     // 24

$date = Carbon::now()->addSeconds(3666);

echo $date->diffInSeconds();                       // -3665.999951
echo $date->diffInMinutes();                       // -61.099998466667
echo $date->diffInHours();                         // -1.0183332975
echo $date->diffInDays();                          // -0.042430553645833

$date = Carbon::create(2016, 1, 5, 22, 40, 32);

echo $date->secondsSinceMidnight();                // 81632
echo $date->secondsUntilEndOfDay();                // 4767.999999

$date1 = Carbon::createMidnightDate(2016, 1, 5);
$date2 = Carbon::createMidnightDate(2017, 3, 15);

echo $date1->diffInDays($date2);                   // 435
echo $date1->diffInWeekdays($date2);               // 311
echo $date1->diffInWeekendDays($date2);            // 124
echo $date1->diffInWeeks($date2);                  // 62.142857142857
echo $date1->diffInMonths($date2);                 // 14.322580645161
echo $date1->diffInQuarters($date2);               // 4.7741935483871
echo $date1->diffInYears($date2);                  // 1.1890410958904

All diffIn*Filtered method take 1 callable filter as required parameter and a date object as optional second parameter, if missing, now is used. You may also pass true as third parameter to get absolute values.

For advanced handle of the week/weekend days, use the following tools:

echo implode(', ', Carbon::getDays());                       // Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday

$saturday = new Carbon('first saturday of 2019');
$sunday = new Carbon('first sunday of 2019');
$monday = new Carbon('first monday of 2019');

echo implode(', ', Carbon::getWeekendDays());                // 6, 0
var_dump($saturday->isWeekend());                            // bool(true)
var_dump($sunday->isWeekend());                              // bool(true)
var_dump($monday->isWeekend());                              // bool(false)

Carbon::setWeekendDays([
    Carbon::SUNDAY,
    Carbon::MONDAY,
]);

echo implode(', ', Carbon::getWeekendDays());                // 0, 1
var_dump($saturday->isWeekend());                            // bool(false)
var_dump($sunday->isWeekend());                              // bool(true)
var_dump($monday->isWeekend());                              // bool(true)

Carbon::setWeekendDays([
    Carbon::SATURDAY,
    Carbon::SUNDAY,
]);
// weekend days and start/end of week or not linked
// start/end of week are driven by the locale

var_dump(Carbon::getWeekStartsAt());                         // int(1)
var_dump(Carbon::getWeekEndsAt());                           // int(0)
var_dump(Carbon::getWeekStartsAt('ar_EG'));                  // int(6)
var_dump(Carbon::getWeekEndsAt('ar_EG'));                    // int(5)

Difference for Humans

It is easier for humans to read 1 month ago compared to 30 days ago. This is a common function seen in most date libraries so I thought I would add it here as well. The lone argument for the function is the other Carbon instance to diff against, and of course it defaults to now() if not specified.

This method will add a phrase after the difference value relative to the instance and the passed in instance. There are 4 possibilities:

• When comparing a value in the past to default now:
  • 1 hour ago
  • 5 months ago
• When comparing a value in the future to default now:
  • 1 hour from now
  • 5 months from now
• When comparing a value in the past to another value:
  • 1 hour before
  • 5 months before
• When comparing a value in the future to another value:
  • 1 hour after
  • 5 months after

You may also pass CarbonInterface::DIFF_ABSOLUTE as a 2nd parameter to remove the modifiers ago, from now, etc : diffForHumans($other, CarbonInterface::DIFF_ABSOLUTE), CarbonInterface::DIFF_RELATIVE_TO_NOW to get modifiers ago or from now, CarbonInterface::DIFF_RELATIVE_TO_OTHER to get the modifiers before or after or CarbonInterface::DIFF_RELATIVE_AUTO (default mode) to get the modifiers either ago/from now if the 2 second argument is null or before/after if not.

You may pass true as a 3rd parameter to use short syntax if available in the locale used : diffForHumans($other, CarbonInterface::DIFF_RELATIVE_AUTO, true).

You may pass a number between 1 and 6 as a 4th parameter to get the difference in multiple parts (more precise diff) : diffForHumans($other, CarbonInterface::DIFF_RELATIVE_AUTO, false, 4).

The $other instance can be a DateTime, a Carbon instance or any object that implement DateTimeInterface, if a string is passed it will be parsed to get a Carbon instance and if null is passed, Carbon::now() will be used instead.

To avoid having too much argument and mix the order, you can use the verbose methods:

• shortAbsoluteDiffForHumans(DateTimeInterface | null $other = null, int $parts = 1)
• longAbsoluteDiffForHumans(DateTimeInterface | null $other = null, int $parts = 1)
• shortRelativeDiffForHumans(DateTimeInterface | null $other = null, int $parts = 1)
• longRelativeDiffForHumans(DateTimeInterface | null $other = null, int $parts = 1)
• shortRelativeToNowDiffForHumans(DateTimeInterface | null $other = null, int $parts = 1)
• longRelativeToNowDiffForHumans(DateTimeInterface | null $other = null, int $parts = 1)
• shortRelativeToOtherDiffForHumans(DateTimeInterface | null $other = null, int $parts = 1)
• longRelativeToOtherDiffForHumans(DateTimeInterface | null $other = null, int $parts = 1)

PS: $other and $parts arguments can be swapped as need.

// The most typical usage is for comments
// The instance is the date the comment was created and its being compared to default now()
echo Carbon::now()->subDays(5)->diffForHumans();               // 5 days ago

echo Carbon::now()->diffForHumans(Carbon::now()->subYear());   // 11 months after

$dt = Carbon::createFromDate(2011, 8, 1);

echo $dt->diffForHumans($dt->copy()->addMonth());                        // 1 month before
echo $dt->diffForHumans($dt->copy()->subMonth());                        // 1 month after

echo Carbon::now()->addSeconds(5)->diffForHumans();                      // 4 seconds from now

echo Carbon::now()->subDays(24)->diffForHumans();                        // 3 weeks ago
echo Carbon::now()->subDays(24)->longAbsoluteDiffForHumans();            // 3 weeks

echo Carbon::parse('2019-08-03')->diffForHumans('2019-08-13');           // 1 week before
echo Carbon::parse('2000-01-01 00:50:32')->diffForHumans('@946684800');  // 50 minutes after

echo Carbon::create(2018, 2, 26, 4, 29, 43)->longRelativeDiffForHumans(Carbon::create(2016, 6, 21, 0, 0, 0), 6); // 1 year 8 months 5 days 4 hours 29 minutes 43 seconds after

You can also change the locale of the string using $date->locale('fr') before the diffForHumans() call. See the localization section for more detail.

Since 2.9.0 diffForHumans() parameters can be passed as an array:

echo Carbon::now()->diffForHumans(['options' => 0]); // 0 seconds ago
echo "\n";
// default options:
echo Carbon::now()->diffForHumans(['options' => Carbon::NO_ZERO_DIFF]); // 1 second ago
echo "\n";
echo Carbon::now()->diffForHumans(['options' => Carbon::JUST_NOW]); // just now
echo "\n";
echo Carbon::now()->subDay()->diffForHumans(['options' => 0]); // 1 day ago
echo "\n";
echo Carbon::now()->subDay()->diffForHumans(['options' => Carbon::ONE_DAY_WORDS]); // yesterday
echo "\n";
echo Carbon::now()->subDays(2)->diffForHumans(['options' => 0]); // 2 days ago
echo "\n";
echo Carbon::now()->subDays(2)->diffForHumans(['options' => Carbon::TWO_DAY_WORDS]); // before yesterday
echo "\n";

// Options can be combined with pipes
$now = Carbon::now();

echo $now->diffForHumans(['options' => Carbon::JUST_NOW | Carbon::ONE_DAY_WORDS | Carbon::TWO_DAY_WORDS]); // just now
echo "\n";

// Reference date for differences is `now` but you can use any other date (string, DateTime or Carbon instance):
$yesterday = $now->copy()->subDay();
echo $now->diffForHumans($yesterday); // 1 day after
echo "\n";
// By default differences methods produce "ago"/"from now" syntax using default reference (now),
// and "after"/"before" with other references
// But you can customize the syntax:
echo $now->diffForHumans($yesterday, ['syntax' => CarbonInterface::DIFF_RELATIVE_TO_NOW]); // 1 day from now
echo "\n";
echo $now->diffForHumans($yesterday, ['syntax' => 0]); // 1 day after
echo "\n";
echo $yesterday->diffForHumans(['syntax' => CarbonInterface::DIFF_ABSOLUTE]); // 1 day
echo "\n";
// Combined with options:
echo $now->diffForHumans($yesterday, [
    'syntax' => CarbonInterface::DIFF_RELATIVE_TO_NOW,
    'options' => Carbon::JUST_NOW | Carbon::ONE_DAY_WORDS | Carbon::TWO_DAY_WORDS,
]); // tomorrow
echo "\n";

// Other parameters:
echo $now->copy()->subHours(5)->subMinutes(30)->subSeconds(10)->diffForHumans([
    'parts' => 2,
]); // 5 hours 30 minutes ago
echo "\n";
echo $now->copy()->subHours(5)->subMinutes(30)->subSeconds(10)->diffForHumans([
    'parts' => 3, // Use -1 or INF for no limit
]); // 5 hours 30 minutes 10 seconds ago
echo "\n";
echo $now->copy()->subHours(5)->subMinutes(30)->subSeconds(10)->diffForHumans([
    'parts' => 3,
    'join' => ', ', // join with commas
]); // 5 hours, 30 minutes, 10 seconds ago
echo "\n";
echo $now->copy()->subHours(5)->subMinutes(30)->subSeconds(10)->diffForHumans([
    'parts' => 3,
    'join' => true, // join with natural syntax as per current locale
]); // 5 hours, 30 minutes and 10 seconds ago
echo "\n";
echo $now->copy()->subHours(5)->subMinutes(30)->subSeconds(10)->locale('fr')->diffForHumans([
    'parts' => 3,
    'join' => true, // join with natural syntax as per current locale
]); // il y a 5 heures, 30 minutes et 10 secondes
echo "\n";
echo $now->copy()->subHours(5)->subMinutes(30)->subSeconds(10)->diffForHumans([
    'parts' => 3,
    'short' => true, // short syntax as per current locale
]); // 5h 30m 10s ago
// 'aUnit' option added in 2.13.0 allows you to prefer "a day", "an hour", etc. over "1 day", "1 hour"
// for singular values when it's available in the current locale
echo $now->copy()->subHour()->diffForHumans([
    'aUnit' => true,
]); // an hour ago

// Before 2.9.0, you need to pass parameters as ordered parameters:
// ->diffForHumans($other, $syntax, $short, $parts, $options)
// and 'join' was not supported

If the argument is omitted or set to null, only Carbon::NO_ZERO_DIFF is enabled. Available options are:

• Carbon::ROUND / Carbon::CEIL / Carbon::FLOOR (none by default): only one of the 3 can be used at a time (other are ignored) and it requires 'parts' to be set. By default, once the diff has as parts as 'parts' setting requested and omit all remaining units.
  • If Carbon::ROUND is enabled, the remaining units are summed and if they are >= 0.5 of the last unit of the diff, this unit will be rounded to the upper value.
  • If Carbon::CEIL is enabled, the remaining units are summed and if they are > 0 of the last unit of the diff, this unit will be rounded to the upper value.
  • If Carbon::FLOOR is enabled, the last diff unit is rounded down. It makes no difference from the default behavior for diffForHumans() as the interval can't have overflow, but this option may be needed when used with CarbonInterval::forHumans() (and unchecked intervals that may have 60 minutes or more, 24 hours or more, etc.). For example: CarbonInterval::make('1 hour and 67 minutes')->forHumans(['parts' => 1]) returns "1 hour" while CarbonInterval::make('1 hour and 67 minutes')->forHumans(['parts' => 1, 'options' => Carbon::FLOOR]) returns "2 hours".
• Carbon::NO_ZERO_DIFF (enabled by default): turns empty diff into 1 second
• Carbon::JUST_NOW disabled by default): turns diff from now to now into "just now"
• Carbon::ONE_DAY_WORDS (disabled by default): turns "1 day from now/ago" to "yesterday/tomorrow"
• Carbon::TWO_DAY_WORDS (disabled by default): turns "2 days from now/ago" to "before yesterday/after
• Carbon::SEQUENTIAL_PARTS_ONLY (disabled by default): will keep only the first sequence of units of the interval, for example if the diff would have been "2 weeks 1 day 34 minutes 12 seconds" as day and minute are not consecutive units, you will get: "2 weeks 1 day".

Use the pipe operator to enable/disable multiple option at once, example: Carbon::ONE_DAY_WORDS | Carbon::TWO_DAY_WORDS

You also can use Carbon::enableHumanDiffOption($option), Carbon::disableHumanDiffOption($option), Carbon::setHumanDiffOptions($options) to change the default options and Carbon::getHumanDiffOptions() to get default options but you should avoid using it as being static it may conflict with calls from other code parts/third-party libraries.

Aliases and reverse methods are provided for semantic purpose:

• from($other = null, $syntax = null, $short = false, $parts = 1, $options = null) (alias of diffForHumans)
• since($other = null, $syntax = null, $short = false, $parts = 1, $options = null) (alias of diffForHumans)
• to($other = null, $syntax = null, $short = false, $parts = 1, $options = null) (inverse result, swap before and future diff)
• until($other = null, $syntax = null, $short = false, $parts = 1, $options = null) (alias of to)
• fromNow($syntax = null, $short = false, $parts = 1, $options = null) (alias of from with first argument omitted unless the first argument is a DateTimeInterface, now used instead), for semantic usage: produce an "3 hours from now"-like string with dates in the future
• ago($syntax = null, $short = false, $parts = 1, $options = null) (alias of fromNow), for semantic usage: produce an "3 hours ago"-like string with dates in the past
• toNow($syntax = null, $short = false, $parts = 1, $options = null) (alias of to with first argument omitted, now used instead)
• timespan($other = null, $timezone = null) calls diffForHumans with options join = ', ' (coma-separated), syntax = CarbonInterface::DIFF_ABSOLUTE (no "ago"/"from now"/"before"/"after" wording), options = CarbonInterface::NO_ZERO_DIFF (no "just now"/"yesterday"/"tomorrow" wording), parts = -1 (no limits) In this mode, you can't change options but you can pass an optional date to compare with or a string + timezone to parse to get this date.

Modifiers

These group of methods perform helpful modifications to the current instance. Most of them are self explanatory from their names... or at least should be. You'll also notice that the startOfXXX(), next() and previous() methods set the time to 00:00:00 and the endOfXXX() methods set the time to 23:59:59 for unit bigger than days.

The only one slightly different is the average() function. It moves your instance to the middle date between itself and the provided Carbon argument.

The powerful native modify() method of DateTime is available untouched. But we also provide an enhanced version of it: change() that allows some additional syntax like "next 3pm" and that is called internally by ->next() and ->previous().

$dt = new Carbon('2012-01-31 15:32:45.654321');
echo $dt->startOfSecond()->format('s.u');          // 45.000000


$dt = new Carbon('2012-01-31 15:32:45.654321');
echo $dt->endOfSecond()->format('s.u');            // 45.999999

$dt = new Carbon('2012-01-31 15:32:45.654321');
echo $dt->startOf('second')->format('s.u');        // 45.000000

$dt = new Carbon('2012-01-31 15:32:45.654321');
echo $dt->endOf('second')->format('s.u');          // 45.999999
// ->startOf() and ->endOf() are dynamic equivalents to those methods

$dt = Carbon::create(2012, 1, 31, 15, 32, 45);
echo $dt->startOfMinute();                         // 2012-01-31 15:32:00

$dt = Carbon::create(2012, 1, 31, 15, 32, 45);
echo $dt->endOfMinute();                           // 2012-01-31 15:32:59

$dt = Carbon::create(2012, 1, 31, 15, 32, 45);
echo $dt->startOfHour();                           // 2012-01-31 15:00:00

$dt = Carbon::create(2012, 1, 31, 15, 32, 45);
echo $dt->endOfHour();                             // 2012-01-31 15:59:59

$dt = Carbon::create(2012, 1, 31, 15, 32, 45);
echo Carbon::getMidDayAt();                        // 12
echo $dt->midDay();                                // 2012-01-31 12:00:00
Carbon::setMidDayAt(13);
echo Carbon::getMidDayAt();                        // 13
echo $dt->midDay();                                // 2012-01-31 13:00:00
Carbon::setMidDayAt(12);

$dt = Carbon::create(2012, 1, 31, 12, 0, 0);
echo $dt->startOfDay();                            // 2012-01-31 00:00:00

$dt = Carbon::create(2012, 1, 31, 12, 0, 0);
echo $dt->endOfDay();                              // 2012-01-31 23:59:59

$dt = Carbon::create(2012, 1, 31, 12, 0, 0);
echo $dt->startOfMonth();                          // 2012-01-01 00:00:00

$dt = Carbon::create(2012, 1, 31, 12, 0, 0);
echo $dt->endOfMonth();                            // 2012-01-31 23:59:59

$dt = Carbon::create(2012, 1, 31, 12, 0, 0);
echo $dt->startOfYear();                           // 2012-01-01 00:00:00

$dt = Carbon::create(2012, 1, 31, 12, 0, 0);
echo $dt->endOfYear();                             // 2012-12-31 23:59:59

$dt = Carbon::create(2012, 1, 31, 12, 0, 0);
echo $dt->startOfDecade();                         // 2010-01-01 00:00:00

$dt = Carbon::create(2012, 1, 31, 12, 0, 0);
echo $dt->endOfDecade();                           // 2019-12-31 23:59:59

$dt = Carbon::create(2012, 1, 31, 12, 0, 0);
echo $dt->startOfCentury();                        // 2001-01-01 00:00:00

$dt = Carbon::create(2012, 1, 31, 12, 0, 0);
echo $dt->endOfCentury();                          // 2100-12-31 23:59:59

$dt = Carbon::create(2012, 1, 31, 12, 0, 0);
echo $dt->startOfWeek();                           // 2012-01-30 00:00:00
var_dump($dt->dayOfWeek == Carbon::MONDAY);        // bool(true) : ISO8601 week starts on Monday

$dt = Carbon::create(2012, 1, 31, 12, 0, 0);
echo $dt->endOfWeek();                             // 2012-02-05 23:59:59
var_dump($dt->dayOfWeek == Carbon::SUNDAY);        // bool(true) : ISO8601 week ends on Sunday

$dt = Carbon::create(2012, 1, 31, 12, 0, 0);
echo $dt->next(Carbon::WEDNESDAY);                 // 2012-02-01 00:00:00
var_dump($dt->dayOfWeek == Carbon::WEDNESDAY);     // bool(true)
echo $dt->next('Wednesday');                       // 2012-02-08 00:00:00
echo $dt->next('04:00');                           // 2012-02-08 04:00:00
echo $dt->next('12:00');                           // 2012-02-08 12:00:00
echo $dt->next('04:00');                           // 2012-02-09 04:00:00

$dt = Carbon::create(2012, 1, 1, 12, 0, 0);
echo $dt->next();                                  // 2012-01-08 00:00:00

$dt = Carbon::create(2012, 1, 31, 12, 0, 0);
echo $dt->previous(Carbon::WEDNESDAY);             // 2012-01-25 00:00:00
var_dump($dt->dayOfWeek == Carbon::WEDNESDAY);     // bool(true)

$dt = Carbon::create(2012, 1, 1, 12, 0, 0);
echo $dt->previous();                              // 2011-12-25 00:00:00

$start = Carbon::create(2014, 1, 1, 0, 0, 0);
$end = Carbon::create(2014, 1, 30, 0, 0, 0);
echo $start->average($end);                        // 2014-01-15 12:00:00

echo Carbon::create(2014, 5, 30, 0, 0, 0)->firstOfMonth();                       // 2014-05-01 00:00:00
echo Carbon::create(2014, 5, 30, 0, 0, 0)->firstOfMonth(Carbon::MONDAY);         // 2014-05-05 00:00:00
echo Carbon::create(2014, 5, 30, 0, 0, 0)->lastOfMonth();                        // 2014-05-31 00:00:00
echo Carbon::create(2014, 5, 30, 0, 0, 0)->lastOfMonth(Carbon::TUESDAY);         // 2014-05-27 00:00:00
echo Carbon::create(2014, 5, 30, 0, 0, 0)->nthOfMonth(2, Carbon::SATURDAY);      // 2014-05-10 00:00:00

echo Carbon::create(2014, 5, 30, 0, 0, 0)->firstOfQuarter();                     // 2014-04-01 00:00:00
echo Carbon::create(2014, 5, 30, 0, 0, 0)->firstOfQuarter(Carbon::MONDAY);       // 2014-04-07 00:00:00
echo Carbon::create(2014, 5, 30, 0, 0, 0)->lastOfQuarter();                      // 2014-06-30 00:00:00
echo Carbon::create(2014, 5, 30, 0, 0, 0)->lastOfQuarter(Carbon::TUESDAY);       // 2014-06-24 00:00:00
echo Carbon::create(2014, 5, 30, 0, 0, 0)->nthOfQuarter(2, Carbon::SATURDAY);    // 2014-04-12 00:00:00
echo Carbon::create(2014, 5, 30, 0, 0, 0)->startOfQuarter();                     // 2014-04-01 00:00:00
echo Carbon::create(2014, 5, 30, 0, 0, 0)->endOfQuarter();                       // 2014-06-30 23:59:59

echo Carbon::create(2014, 5, 30, 0, 0, 0)->firstOfYear();                        // 2014-01-01 00:00:00
echo Carbon::create(2014, 5, 30, 0, 0, 0)->firstOfYear(Carbon::MONDAY);          // 2014-01-06 00:00:00
echo Carbon::create(2014, 5, 30, 0, 0, 0)->lastOfYear();                         // 2014-12-31 00:00:00
echo Carbon::create(2014, 5, 30, 0, 0, 0)->lastOfYear(Carbon::TUESDAY);          // 2014-12-30 00:00:00
echo Carbon::create(2014, 5, 30, 0, 0, 0)->nthOfYear(2, Carbon::SATURDAY);       // 2014-01-11 00:00:00

echo Carbon::create(2018, 2, 23, 0, 0, 0)->nextWeekday();                        // 2018-02-26 00:00:00
echo Carbon::create(2018, 2, 23, 0, 0, 0)->previousWeekday();                    // 2018-02-22 00:00:00
echo Carbon::create(2018, 2, 21, 0, 0, 0)->nextWeekendDay();                     // 2018-02-24 00:00:00
echo Carbon::create(2018, 2, 21, 0, 0, 0)->previousWeekendDay();                 // 2018-02-18 00:00:00

Rounding is also available for any unit:

$dt = new Carbon('2012-01-31 15:32:45.654321');
echo $dt->roundMillisecond()->format('H:i:s.u');   // 15:32:45.654000

$dt = new Carbon('2012-01-31 15:32:45.654321');
echo $dt->roundSecond()->format('H:i:s.u');        // 15:32:46.000000

$dt = new Carbon('2012-01-31 15:32:45.654321');
echo $dt->floorSecond()->format('H:i:s.u');        // 15:32:45.000000

$dt = new Carbon('2012-01-31 15:32:15');
echo $dt->roundMinute()->format('H:i:s');          // 15:32:00

$dt = new Carbon('2012-01-31 15:32:15');
echo $dt->ceilMinute()->format('H:i:s');           // 15:33:00

// and so on up to millennia!

// precision rounding can be set, example: rounding to ten minutes
$dt = new Carbon('2012-01-31 15:32:15');
echo $dt->roundMinute(10)->format('H:i:s');        // 15:30:00

// and round, floor and ceil methods are shortcut for second rounding:
$dt = new Carbon('2012-01-31 15:32:45.654321');
echo $dt->round()->format('H:i:s.u');              // 15:32:46.000000
$dt = new Carbon('2012-01-31 15:32:45.654321');
echo $dt->floor()->format('H:i:s.u');              // 15:32:45.000000
$dt = new Carbon('2012-01-31 15:32:45.654321');
echo $dt->ceil()->format('H:i:s.u');               // 15:32:46.000000

// you can also pass the unit dynamically (and still precision as second argument):
$dt = new Carbon('2012-01-31');
echo $dt->roundUnit('month', 2)->format('Y-m-d');  // 2012-01-01
$dt = new Carbon('2012-01-31');
echo $dt->floorUnit('month')->format('Y-m-d');     // 2012-01-01
$dt = new Carbon('2012-01-31');
echo $dt->ceilUnit('month', 4)->format('Y-m-d');   // 2012-05-01

Constants

The following constants are defined in the Carbon class.

// These getters specifically return integers, ie intval()
var_dump(Carbon::SUNDAY);                          // int(0)
var_dump(Carbon::MONDAY);                          // int(1)
var_dump(Carbon::TUESDAY);                         // int(2)
var_dump(Carbon::WEDNESDAY);                       // int(3)
var_dump(Carbon::THURSDAY);                        // int(4)
var_dump(Carbon::FRIDAY);                          // int(5)
var_dump(Carbon::SATURDAY);                        // int(6)

var_dump(Carbon::YEARS_PER_CENTURY);               // int(100)
var_dump(Carbon::YEARS_PER_DECADE);                // int(10)
var_dump(Carbon::MONTHS_PER_YEAR);                 // int(12)
var_dump(Carbon::WEEKS_PER_YEAR);                  // int(52)
var_dump(Carbon::DAYS_PER_WEEK);                   // int(7)
var_dump(Carbon::HOURS_PER_DAY);                   // int(24)
var_dump(Carbon::MINUTES_PER_HOUR);                // int(60)
var_dump(Carbon::SECONDS_PER_MINUTE);              // int(60)

$dt = Carbon::createFromDate(2012, 10, 6);
if ($dt->dayOfWeek === Carbon::SATURDAY) {
    echo 'Place bets on Ottawa Senators Winning!';
}

Serialization

The Carbon instances can be serialized (including CarbonImmutable, CarbonInterval and CarbonPeriod).

$dt = Carbon::create(2012, 12, 25, 20, 30, 00, 'Europe/Moscow');

echo serialize($dt);                                              // O:13:"Carbon\Carbon":4:{s:4:"date";s:26:"2012-12-25 20:30:00.000000";s:13:"timezone_type";i:3;s:8:"timezone";s:13:"Europe/Moscow";s:18:"dumpDateProperties";a:2:{s:4:"date";s:26:"2012-12-25 20:30:00.000000";s:8:"timezone";s:13:"Europe/Moscow";}}
// same as:
echo $dt->serialize();                                            // O:13:"Carbon\Carbon":4:{s:4:"date";s:26:"2012-12-25 20:30:00.000000";s:13:"timezone_type";i:3;s:8:"timezone";s:13:"Europe/Moscow";s:18:"dumpDateProperties";a:2:{s:4:"date";s:26:"2012-12-25 20:30:00.000000";s:8:"timezone";s:13:"Europe/Moscow";}}

$dt = 'O:13:"Carbon\Carbon":3:{s:4:"date";s:26:"2012-12-25 20:30:00.000000";s:13:"timezone_type";i:3;s:8:"timezone";s:13:"Europe/Moscow";}';

echo unserialize($dt)->format('Y-m-d\TH:i:s.uP T');               // 2012-12-25T20:30:00.000000+04:00 MSK
// same as:
echo Carbon::fromSerialized($dt)->format('Y-m-d\TH:i:s.uP T');    // 2012-12-25T20:30:00.000000+04:00 MSK

// you can pass options to Carbon::fromSerialized the same way as you can with unserialize
echo Carbon::fromSerialized(
    $dt,
    ['allowed_classes' => [Carbon::class]],
)->format('Y-m-d\TH:i:s.uP T'); // 2012-12-25T20:30:00.000000+04:00 MSK

JSON

The Carbon instances can be encoded to and decoded from JSON. Since the version 2.4, we explicitly require the PHP JSON extension. It should have no impact as this extension is bundled by default with PHP. If the extension is disabled, be aware you will be locked on 2.3. But you still can use --ignore-platform-reqs on composer update/install to upgrade then polyfill the missing JsonSerializable interface by including JsonSerializable.php.

$dt = Carbon::create(2012, 12, 25, 20, 30, 00, 'Europe/Moscow');
echo json_encode($dt);
// "2012-12-25T16:30:00.000000Z"

$json = '{"date":"2012-12-25 20:30:00.000000","timezone_type":3,"timezone":"Europe\/Moscow"}';
$dt = Carbon::__set_state(json_decode($json, true));
echo $dt->format('Y-m-d\TH:i:s.uP T');
// 2012-12-25T20:30:00.000000+04:00 MSK

You can use settings(['toJsonFormat' => $format]) to customize the serialization.

$dt = Carbon::create(2012, 12, 25, 20, 30, 00, 'Europe/Moscow')->settings([
    'toJsonFormat' => function ($date) {
        return $date->getTimestamp();
    },
]);
echo json_encode($dt); // 1356453000

If you want to apply this globally, first consider using factory, else or if you use Carbon 1 you can use:

$dt = Carbon::create(2012, 12, 25, 20, 30, 00, 'Europe/Moscow');
Carbon::serializeUsing(function ($date) {
    return $date->valueOf();
});
echo json_encode($dt); // 1356453000000

// Call serializeUsing with null to reset the serializer:
Carbon::serializeUsing(null);

The jsonSerialize() method allows you to call the function given to Carbon::serializeUsing() or the result of toJson() if no custom serialization specified.

Macro

You may be familiar with the macro concept if you are used to working with Laravel and objects such as response or collections. Carbon macros works just like the Laravel Macroable Trait.

Call the Carbon::macro() method with the name of your macro as the first argument and a closure as the second argument. This will make the closure action available on all Carbon instances.

Carbon::macro('diffFromYear', static function ($year, $absolute = false, $short = false, $parts = 1) {
    return self::this()->diffForHumans(Carbon::create($year, 1, 1, 0, 0, 0), $absolute, $short, $parts);
});

// Can be called on Carbon instances:
//    self::context() = current instance ($this) or null when called statically
//    self::this() = current instance ($this) or Carbon::now() when called statically
echo Carbon::parse('2020-01-12 12:00:00')->diffFromYear(2019);                 // 1 year after
echo "\n";
echo Carbon::parse('2020-01-12 12:00:00')->diffFromYear(2019, true);           // 1 year
echo "\n";
echo Carbon::parse('2020-01-12 12:00:00')->diffFromYear(2019, true, true);     // 1yr
echo "\n";
echo Carbon::parse('2020-01-12 12:00:00')->diffFromYear(2019, true, true, 5);  // 1yr 1w 4d 12h

// Can also be called statically, in this case self::this() = Carbon::now()
echo "\n";
echo Carbon::diffFromYear(2017);                                               // 8 years after

Note that the closure is preceded by static and uses self::this() (available since version 2.25.0) instead of $this. This is the standard way to create Carbon macros, and this also applies to macros on other classes (CarbonImmutable, CarbonInterval and CarbonPeriod).

By following this pattern you ensure other developers of you team (and future you) can rely safely on the assertion: Carbon::anyMacro() is equivalent to Carbon::now()->anyMacro(). This makes the usage of macros consistent and predictable and ensures developers that any macro can be called safely either statically or dynamically.

The sad part is IDE will not natively your macro method (no auto-completion for the method diffFromYear in the example above). But it's no longer a problem thanks to our CLI tool: carbon-cli that allows you to generate IDE helper files for your mixins and macros.

Macros are the perfect tool to output dates with some settings or user preferences.

// Let assume you get user settings from the browser or preferences stored in a database
$userTimezone = 'Europe/Paris';
$userLanguage = 'fr_FR';

Carbon::macro('formatForUser', static function () use ($userTimezone, $userLanguage) {
    $date = self::this()->copy()->tz($userTimezone)->locale($userLanguage);

    return $date->calendar(); // or ->isoFormat($customFormat), ->diffForHumans(), etc.
});

// Then let assume you store all your dates/times in UTC (because you definitely should)
$dateString = '2010-01-23 10:00:00'; // Get this from your database or any input

// Then now you can easily display any date in a page/e-mail using those user settings and the chosen format
echo Carbon::parse($dateString, 'UTC')->formatForUser();   // 23/01/2010
echo "\n";
echo Carbon::tomorrow()->formatForUser();                  // Demain à 02:00
echo "\n";
echo Carbon::now()->subDays(3)->formatForUser();           // mercredi dernier à 08:05

Macros can also be grouped in classes and be applied with mixin()

class BeerDayCarbonMixin
{
    public function nextBeerDay()
    {
        return static function () {
            return self::this()->modify('next wednesday');
        };
    }

    public function previousBeerDay()
    {
        return static function () {
            return self::this()->modify('previous wednesday');
        };
    }
}

Carbon::mixin(new BeerDayCarbonMixin());

$date = Carbon::parse('First saturday of December 2018');

echo $date->previousBeerDay();                                                 // 2018-11-28 00:00:00
echo "\n";
echo $date->nextBeerDay();                                                     // 2018-12-05 00:00:00

Since Carbon 2.23.0, it's also possible to shorten the mixin syntax using traits:

trait BeerDayCarbonTrait
{
    public function nextBeerDay()
    {
        return $this->modify('next wednesday');
    }

    public function previousBeerDay()
    {
        return $this->modify('previous wednesday');
    }
}

Carbon::mixin(BeerDayCarbonTrait::class);

$date = Carbon::parse('First saturday of December 2018');

echo $date->previousBeerDay();                                                 // 2018-11-28 00:00:00
echo "\n";
echo $date->nextBeerDay();                                                     // 2018-12-05 00:00:00

You can check if a macro (mixin included) is available with hasMacro() and retrieve the macro closure with getMacro()

var_dump(Carbon::hasMacro('previousBeerDay'));                                 // bool(true)
var_dump(Carbon::hasMacro('diffFromYear'));                                    // bool(true)
echo "\n";
var_dump(Carbon::hasMacro('dontKnowWhat'));                                    // bool(false)

A macro starting with get followed by an uppercase letter will automatically provide a dynamic getter whilst a macro starting with set and followed by an uppercase letter will provide a dynamic setter:

// Let's say a school year starts 5 months before the start of the year, so the school year of 2018 actually begins in August 2017 and ends in July 2018,
// Then you can create get/set method this way:
Carbon::macro('setSchoolYear', static function ($schoolYear) {
    $date = self::this();
    $date->year = $schoolYear;

    if ($date->month > 7) {
        $date->year--;
    }
});
Carbon::macro('getSchoolYear', static function () {
    $date = self::this();
    $schoolYear = $date->year;

    if ($date->month > 7) {
        $schoolYear++;
    }

    return $schoolYear;
});
// This will make getSchoolYear/setSchoolYear as usual, but get/set prefix will also enable
// the getter and setter methods for the ->schoolYear property.

$date = Carbon::parse('2016-06-01');

var_dump($date->schoolYear);                   // int(2016)
$date->addMonths(3);
var_dump($date->schoolYear);                   // int(2017)
$date->schoolYear++;
var_dump($date->format('Y-m-d'));              // string(10) "2017-09-01"
$date->schoolYear = 2020;
var_dump($date->format('Y-m-d'));              // string(10) "2019-09-01"

You can also intercept any other call with generic macro:

Carbon::genericMacro(static function ($method) {
    // As an example we will convert firstMondayOfDecember into first Monday Of December to get strings that
    // DateTime can parse.
    $time = preg_replace('/[A-Z]/', ' $0', $method);

    try {
        return self::this()->modify($time);
    } catch (\Throwable $exception) {
        if (stripos($exception->getMessage(), 'Failed to parse') !== false) {
            // When throwing BadMethodCallException from inside a generic macro will go to next generic macro
            // if there are other registered.
            throw new \BadMethodCallException('Try next macro', 0, $exception);
        }

        // Other exceptions thrown will not be caught
        throw $exception;
    }
}, 1 /* you can optionally pass a priority as a second argument, 0 by default, can be negative, higher priority ran first */);
// Generic macro get the asked method name as first argument, and method arguments as others.
// They can return any value.
// They can be added via "genericMacros" setting and this setting has precedence over statically declared generic macros.

$date = Carbon::parse('2016-06-01');

echo $date->nextSunday();                  // 2016-06-05 00:00:00
echo "\n";
echo $date->lastMondayOfPreviousMonth();   // 2016-05-30 00:00:00
Carbon::resetMacros(); // resetMacros remove all macros and generic macro declared statically

And guess what? all macro methods are also available on CarbonInterval and CarbonPeriod classes.

CarbonInterval::macro('twice', static function () {
    return self::this()->times(2);
});
echo CarbonInterval::day()->twice()->forHumans(); // 2 days
$interval = CarbonInterval::hours(2)->addMinutes(15)->twice();
echo $interval->forHumans(['short' => true]); // 4h 30m

CarbonPeriod::macro('countWeekdays', static function () {
    return self::this()->filter('isWeekday')->count();
});
echo CarbonPeriod::create('2017-11-01', '2017-11-30')->countWeekdays();  // 22
echo CarbonPeriod::create('2017-12-01', '2017-12-31')->countWeekdays();  // 21

We provide a PHPStan extension out of the box you can include in your phpstan.neon:

includes:
    - vendor/nesbot/carbon/extension.neon
parameters:
    bootstrapFiles:
        # You will also need to add here the file
        # that enable your macros and mixins:
        - config/bootstrap.php

If you're using Laravel, you can consider using larastan which provides a complete support of Laravel features in PHPStan (including Carbon macros). Alternatively to include the neon file, you can install phpstan/extension-installer:

composer require --dev phpstan/phpstan phpstan/extension-installer

Then add the file where your Carbon macros and mixins are defined in the bootstrapFiles entry:

parameters:
    bootstrapFiles:
        - config/bootstrap.php

📦 Carbon extension libraries

Check cmixin/business-time (that includes cmixin/business-day) to handle both holidays and business opening hours with a lot of advanced features.

Check cmixin/season to check if date is in a given season, which season of the year is a date, or when season starts and ends.

Check cmixin/enhanced-period for more period features: `touchesWith()`, `overlapsWith()`, `duration()`, `diff()`, `diffAny()`, etc.

Check Carbonite for more advanced Carbon testing features.

🙌 More macros and mixins below shared by users

class CurrentDaysCarbonMixin
{
    /**
     * Get the all dates of week
     *
     * @return array
     */
    public static function getCurrentWeekDays()
    {
        return static function () {
            $startOfWeek = self::this()->startOfWeek()->subDay();
            $weekDays = [];

            for ($i = 0; $i < static::DAYS_PER_WEEK; $i++) {
                $weekDays[] = $startOfWeek->addDay()->startOfDay()->copy();
            }

            return $weekDays;
        };
    }

    /**
     * Get the all dates of month
     *
     * @return array
     */
    public static function getCurrentMonthDays()
    {
        return static function () {
            $date = self::this();
            $startOfMonth = $date->copy()->startOfMonth()->subDay();
            $endOfMonth = $date->copy()->endOfMonth()->format('d');
            $monthDays = [];

            for ($i = 0; $i < $endOfMonth; $i++)
            {
                $monthDays[] = $startOfMonth->addDay()->startOfDay()->copy();
            }

            return $monthDays;
        };
    }
}

Carbon::mixin(new CurrentDaysCarbonMixin());

function dumpDateList($dates) {
    echo substr(implode(', ', $dates), 0, 100).'...';
}

dumpDateList(Carbon::getCurrentWeekDays());                       // 2025-06-30 00:00:00, 2025-07-01 00:00:00, 2025-07-02 00:00:00, 2025-07-03 00:00:00, 2025-07-04 00:00...
dumpDateList(Carbon::getCurrentMonthDays());                      // 2025-07-01 00:00:00, 2025-07-02 00:00:00, 2025-07-03 00:00:00, 2025-07-04 00:00:00, 2025-07-05 00:00...
dumpDateList(Carbon::now()->subMonth()->getCurrentWeekDays());    // 2025-06-02 00:00:00, 2025-06-03 00:00:00, 2025-06-04 00:00:00, 2025-06-05 00:00:00, 2025-06-06 00:00...
dumpDateList(Carbon::now()->subMonth()->getCurrentMonthDays());   // 2025-06-01 00:00:00, 2025-06-02 00:00:00, 2025-06-03 00:00:00, 2025-06-04 00:00:00, 2025-06-05 00:00...

Credit: meteguerlek (#1191).

Carbon::macro('toAtomStringWithNoTimezone', static function () {
    return self::this()->format('Y-m-d\TH:i:s');
});
echo Carbon::parse('2021-06-16 20:08:34')->toAtomStringWithNoTimezone(); // 2021-06-16T20:08:34

Credit: afrojuju1 (#1063).

Carbon::macro('easterDate', static function ($year) {
    return Carbon::createMidnightDate($year, 3, 21)->addDays(easter_days($year));
});
echo Carbon::easterDate(2015)->format('d/m'); // 05/04
echo Carbon::easterDate(2016)->format('d/m'); // 27/03
echo Carbon::easterDate(2017)->format('d/m'); // 16/04
echo Carbon::easterDate(2018)->format('d/m'); // 01/04
echo Carbon::easterDate(2019)->format('d/m'); // 21/04

Credit: andreisena, 36864 (#1052).

Check cmixin/business-day for a more complete holidays handler.

Carbon::macro('datePeriod', static function ($startDate, $endDate) {
    return new DatePeriod($startDate, new DateInterval('P1D'), $endDate);
});
foreach (Carbon::datePeriod(Carbon::createMidnightDate(2019, 3, 28), Carbon::createMidnightDate(2019, 4, 3)) as $date) {
    echo $date->format('Y-m-d') . "\n";
}
/*
2019-03-28
2019-03-29
2019-03-30
2019-03-31
2019-04-01
2019-04-02
*/

Credit: reinink (#132).

Carbon::macro('formatBuddhist', static function (string $format): string {
    $self = self::this();

    $format = strtr($format, [
        'o' => '[{1}]',
        'Y' => '[{2}]',
        'y' => '[{3}]',
    ]);

    $function = $self->localFormatFunction ?: static::$formatFunction;

    if (!$function) {
        $format = $self->rawFormat($format);
    } else if (\is_string($function) && method_exists($self, $function)) {
        $format = [$self, $function];
        $format = $function(...\func_get_args());
    }

    $buddhistYear = $self->year + 543;

    return strtr($format, [
        '[{1}]' => $self->format('o') + 543,
        '[{2}]' => $buddhistYear,
        '[{3}]' => str_pad($buddhistYear % 100, 2, '0', STR_PAD_LEFT),
    ]);
});
echo Carbon::parse('2024-02-29 10.55.32')->formatBuddhist('Y-m-d H:i:s'); // 2567-02-29 10:55:32
echo Carbon::parse('2024-02-29 10.55.32')->formatBuddhist('d/m/y');       // 29/02/67

From on original idea of: mean-cj (#2954).

class UserTimezoneCarbonMixin
{
    public $userTimeZone;

    /**
     * Set user timezone, will be used before format function to apply current user timezone
     *
     * @param $timezone
     */
    public function setUserTimezone()
    {
        $mixin = $this;

        return static function ($timezone) use ($mixin) {
            $mixin->userTimeZone = $timezone;
        };
    }

    /**
     * Returns date formatted according to given format.
     *
     * @param string $format
     *
     * @return string
     *
     * @link https://www.php.net/manual/en/datetime.format.php
     */
    public function tzFormat()
    {
        $mixin = $this;

        return static function ($format) use ($mixin) {
            $date = self::this();

            if (!is_null($mixin->userTimeZone)) {
                $date->timezone($mixin->userTimeZone);
            }

            return $date->format($format);
        };
    }
}

Carbon::mixin(new UserTimezoneCarbonMixin());

Carbon::setUserTimezone('Europe/Berlin');
echo Carbon::createFromTime(12, 0, 0, 'UTC')->tzFormat('H:i'); // 14:00
echo Carbon::createFromTime(15, 0, 0, 'UTC')->tzFormat('H:i'); // 17:00
Carbon::setUserTimezone('America/Toronto');
echo Carbon::createFromTime(12, 0, 0, 'UTC')->tzFormat('H:i'); // 08:00
echo Carbon::createFromTime(15, 0, 0, 'UTC')->tzFormat('H:i'); // 11:00

Credit: thiagocordeiro (#927).

Whilst using a macro is the recommended way to add new methods or behaviour to Carbon, you can go further and extend the class itself which allows some alternative ways to override the primary methods; parse, format and createFromFormat.

class MyDateClass extends Carbon
{
    protected static $formatFunction = 'translatedFormat';

    protected static $createFromFormatFunction = 'createFromLocaleFormat';

    protected static $parseFunction = 'myCustomParse';

    public static function myCustomParse($string)
    {
        return static::rawCreateFromFormat('d m Y', $string);
    }
}

$date = MyDateClass::parse('20 12 2001')->locale('de');
echo $date->format('jS F y');            // 20. Dezember 01
echo "\n";

$date = MyDateClass::createFromFormat('j F Y', 'pt', '20 fevereiro 2001')->locale('pt');

echo $date->format('d/m/Y');             // 20/02/2001
echo "\n";

// Note than you can still access native methods using rawParse, rawFormat and rawCreateFromFormat:
$date = MyDateClass::rawCreateFromFormat('j F Y', '20 February 2001', 'UTC')->locale('pt');

echo $date->rawFormat('jS F y');         // 20th February 01
echo "\n";

$date = MyDateClass::rawParse('2001-02-01', 'UTC')->locale('pt');

echo $date->format('jS F y');            // 1º fevereiro 01
echo "\n";

The following macro allow you to choose a timezone using only the city name (omitting continent). Perfect to make your unit tests more fluent:

Carbon::macro('goTo', function (string $city) {
    static $cities = null;

    if ($cities === null) {
        foreach (DateTimeZone::listIdentifiers() as $identifier) {
            $chunks = explode('/', $identifier);

            if (isset($chunks[1])) {
                $id = strtolower(end($chunks));
                $cities[$id] = $identifier;
            }
        }
    }

    $city = str_replace(' ', '_', strtolower($city));

    if (!isset($cities[$city])) {
        throw new InvalidArgumentException("$city not found.");
    }

    return $this->tz($cities[$city]);
});

echo Carbon::now()->goTo('Chicago')->tzName; // America/Chicago
echo "\n";
echo Carbon::now()->goTo('Buenos Aires')->tzName; // America/Argentina/Buenos_Aires

CarbonInterval

The CarbonInterval class is inherited from the PHP DateInterval class.

<?php
class CarbonInterval extends \DateInterval
{
    // code here
}

You can create an instance in the following ways:

echo CarbonInterval::createFromFormat('H:i:s', '10:20:00'); // 10 hours 20 minutes
echo "\n";
echo CarbonInterval::year();                           // 1 year
echo "\n";
echo CarbonInterval::months(3);                        // 3 months
echo "\n";
echo CarbonInterval::days(3)->addSeconds(32);          // 3 days 32 seconds
echo "\n";
echo CarbonInterval::weeks(3);                         // 3 weeks
echo "\n";
echo CarbonInterval::days(23);                         // 3 weeks 2 days
echo "\n";
// years, months, weeks, days, hours, minutes, seconds, microseconds
echo CarbonInterval::create(2, 0, 5, 1, 1, 2, 7, 123); // 2 years 5 weeks 1 day 1 hour 2 minutes 7 seconds
echo "\n";
echo CarbonInterval::createFromDateString('3 months'); // 3 months

Be careful, Carbon 2 accepts only integer unit values by default, which means: CarbonInterval::days(3.5) produces a [3 days and 0 hours] interval. In Carbon 3, it will cascade decimal part to smaller units. To enable this behavior in Carbon 2, you can call CarbonInterval::enableFloatSetters();.

// Allow decimal numbers
CarbonInterval::enableFloatSetters();
echo CarbonInterval::days(3.5);                        // 3 days 12 hours
echo "\n";
// Disallow decimal numbers
CarbonInterval::enableFloatSetters(false);
echo CarbonInterval::days(3.5);                        // 3 days

You can add/sub any unit to a given existing interval:

$interval = CarbonInterval::months(3);
echo $interval;                                        // 3 months
echo "\n";

$interval->subMonths(1);
echo $interval;                                        // 2 months
echo "\n";

$interval->addDays(15);
echo $interval;                                        // 2 months 2 weeks 1 day

We also provide plus() and minus() method that expect numbers for each unit in the same order than create() and can be used in a convenient way with PHP 8:

$interval = CarbonInterval::months(3);
echo $interval;                          // 3 months
echo "\n";

$interval->minus(months: 1);
echo $interval;                          // 2 months
echo "\n";

$interval->plus(days: 15, hours: 20);
echo $interval;                          // 2 months 2 weeks 1 day 20 hours

If you find yourself inheriting a \DateInterval instance from another library, fear not! You can create a CarbonInterval instance via a friendly instance() function.

$di = new \DateInterval('P1Y2M'); // <== instance from another API
$ci = CarbonInterval::instance($di);
echo get_class($ci);                                   // 'Carbon\CarbonInterval'
echo $ci;                                              // 1 year 2 months

// It creates a new copy of the object when given a CarbonInterval value
$ci2 = CarbonInterval::instance($ci);
var_dump($ci2 === $ci);                                // bool(false)

// but you can tell to return same object if already an instance of  CarbonInterval
$ci3 = CarbonInterval::instance($ci, skipCopy: true);
var_dump($ci3 === $ci);                                // bool(true)

// the same option is available on make()
$ci4 = CarbonInterval::make($ci, skipCopy: true);
var_dump($ci4 === $ci);                                // bool(true)

And as the opposite you can extract a raw DateInterval from CarbonInterval and even cast it in any class that extends DateInterval

$ci = CarbonInterval::days(2);
$di = $ci->toDateInterval();
echo get_class($di);   // 'DateInterval'
echo $di->d;           // 2

// Your custom class can also extends CarbonInterval
class CustomDateInterval extends \DateInterval {}

$di = $ci->cast(\CustomDateInterval::class);
echo get_class($di);   // 'CustomDateInterval'
echo $di->d;           // 2

You can compare intervals the same way than Carbon objects, using equalTo(), notEqualTo() lessThan(), lessThanOrEqualTo(), greaterThan(), greaterThanOrEqualTo(), between(), betweenExcluded(), etc.

Other helpers, but beware the implementation provides helpers to handle weeks but only days are saved. Weeks are calculated based on the total days of the current instance.

echo CarbonInterval::year()->years;                    // 1
echo CarbonInterval::year()->dayz;                     // 0
echo CarbonInterval::days(24)->dayz;                   // 24
echo CarbonInterval::days(24)->daysExcludeWeeks;       // 3
echo CarbonInterval::weeks(3)->days(14)->weeks;        // 2  <-- days setter overwrites the current value
echo CarbonInterval::weeks(3)->addDays(14)->weeks;     // 5
echo CarbonInterval::weeks(3)->weeks;                  // 3
echo CarbonInterval::minutes(3)->weeksAndDays(2, 5);   // 2 weeks 5 days 3 minutes

CarbonInterval extends DateInterval and you can create both using ISO-8601 duration format:

$ci = CarbonInterval::create('P1Y2M3D');
var_dump($ci->isEmpty()); // bool(false)
$ci = new CarbonInterval('PT0S');
var_dump($ci->isEmpty()); // bool(true)

Carbon intervals can be created from human-friendly strings thanks to fromString() method.

CarbonInterval::fromString('2 minutes 15 seconds');
CarbonInterval::fromString('2m 15s'); // or abbreviated

Or create it from an other DateInterval / CarbonInterval object.

$ci = new CarbonInterval(new DateInterval('P1Y2M3D'));
var_dump($ci->isEmpty()); // bool(false)

Note that month abbreviate "mo" to distinguish from minutes and the whole syntax is not case sensitive.

It also has a handy forHumans(), which is mapped as the __toString() implementation, that prints the interval for humans.

CarbonInterval::setLocale('fr');
echo CarbonInterval::create(2, 1)->forHumans();        // 2 ans 1 mois
echo CarbonInterval::hour()->addSeconds(3);            // 1 heure 3 secondes
CarbonInterval::setLocale('en');

forHumans($syntax, $short, $parts, $options) allow the same option arguments as Carbon::diffForHumans() except $parts is set to -1 (no limit) by default. See Carbon::diffForHumans() options.

As you can see, you can change the locale of the string using CarbonInterval::setLocale('fr').

As for Carbon, you can use the make method to return a new instance of CarbonInterval from other interval or strings:

$dateInterval = new DateInterval('P2D');
$carbonInterval = CarbonInterval::month();
echo CarbonInterval::make($dateInterval)->forHumans();       // 2 days
echo CarbonInterval::make($carbonInterval)->forHumans();     // 1 month
echo CarbonInterval::make(5, 'days')->forHumans();           // 5 days
echo CarbonInterval::make('PT3H')->forHumans();              // 3 hours
echo CarbonInterval::make('1h 15m')->forHumans();            // 1 hour 15 minutes
// forHumans has many options, since version 2.9.0, the recommended way is to pass them as an associative array:
echo CarbonInterval::make('1h 15m')->forHumans(['short' => true]); // 1h 15m

// You can create interval from a string in any language:
echo CarbonInterval::parseFromLocale('3 jours et 2 heures', 'fr'); // 3 days 2 hours
// 'fr' stands for French but can be replaced with any locale code.
// if you don't pass the locale parameter, Carbon::getLocale() (current global locale) is used.

$interval = CarbonInterval::make('1h 15m 45s');
echo $interval->forHumans(['join' => true]);                 // 1 hour, 15 minutes and 45 seconds
$esInterval = CarbonInterval::make('1h 15m 45s');
echo $esInterval->forHumans(['join' => true]);               // 1 hour, 15 minutes and 45 seconds
echo $interval->forHumans(['join' => true, 'parts' => 2]);   // 1 hour and 15 minutes
echo $interval->forHumans(['join' => ' - ']);                // 1 hour - 15 minutes - 45 seconds

// Available syntax modes:
// ago/from now (translated in the current locale)
echo $interval->forHumans(['syntax' => CarbonInterface::DIFF_RELATIVE_TO_NOW]);      // 1 hour 15 minutes 45 seconds ago
// before/after (translated in the current locale)
echo $interval->forHumans(['syntax' => CarbonInterface::DIFF_RELATIVE_TO_OTHER]);    // 1 hour 15 minutes 45 seconds before
// default for intervals (no prefix/suffix):
echo $interval->forHumans(['syntax' => CarbonInterface::DIFF_ABSOLUTE]);             // 1 hour 15 minutes 45 seconds

// Available options:
// transform empty intervals into "just now":
echo CarbonInterval::hours(0)->forHumans([
    'options' => CarbonInterface::JUST_NOW,
    'syntax' => CarbonInterface::DIFF_RELATIVE_TO_NOW,
]);                                                                                  // just now
// transform empty intervals into "1 second":
echo CarbonInterval::hours(0)->forHumans([
    'options' => CarbonInterface::NO_ZERO_DIFF,
    'syntax' => CarbonInterface::DIFF_RELATIVE_TO_NOW,
]);                                                                                  // 1 second ago
// transform "1 day ago"/"1 day from now" into "yesterday"/"tomorrow":
echo CarbonInterval::day()->forHumans([
    'options' => CarbonInterface::ONE_DAY_WORDS,
    'syntax' => CarbonInterface::DIFF_RELATIVE_TO_NOW,
]);                                                                                  // 1 day ago
// transform "2 days ago"/"2 days from now" into "before yesterday"/"after tomorrow":
echo CarbonInterval::days(2)->forHumans([
    'options' => CarbonInterface::TWO_DAY_WORDS,
    'syntax' => CarbonInterface::DIFF_RELATIVE_TO_NOW,
]);                                                                                  // 2 days ago
// options can be piped:
echo CarbonInterval::days(2)->forHumans([
    'options' => CarbonInterface::ONE_DAY_WORDS | CarbonInterface::TWO_DAY_WORDS,
    'syntax' => CarbonInterface::DIFF_RELATIVE_TO_NOW,
]);                                                                                  // 2 days ago

// Before version 2.9.0, parameters could only be passed sequentially:
// $interval->forHumans($syntax, $short, $parts, $options)
// and join parameter was not available

The add, sub (or subtract), times, shares, multiply and divide methods allow to do proceed intervals calculations:

$interval = CarbonInterval::make('7h 55m');
$interval->add(CarbonInterval::make('17h 35m'));
$interval->subtract(10, 'minutes');
// add(), sub() and subtract() can take DateInterval, CarbonInterval, interval as string or 2 arguments factor and unit
$interval->times(3);
echo $interval->forHumans();                                       // 72 hours 240 minutes
echo "\n";
$interval->shares(7);
echo $interval->forHumans();                                       // 10 hours 34 minutes
echo "\n";
// As you can see add(), times() and shares() operate naively a rounded calculation on each unit

// You also can use multiply() of divide() to cascade units and get precise calculation:
echo CarbonInterval::make('19h 55m')->multiply(3)->forHumans();    // 2 days 11 hours 45 minutes
echo "\n";
echo CarbonInterval::make('19h 55m')->divide(3)->forHumans();      // 6 hours 38 minutes 20 seconds

You get pure calculation from your input unit by unit. To cascade minutes into hours, hours into days etc. Use the cascade method:

echo $interval->forHumans();             // 10 hours 34 minutes
echo $interval->cascade()->forHumans();  // 10 hours 34 minutes

Default factors are:

• 1 minute = 60 seconds
• 1 hour = 60 minutes
• 1 day = 24 hour
• 1 week = 7 days
• 1 month = 4 weeks
• 1 year = 12 months

CarbonIntervals do not carry context so they cannot be more precise (no DST, no leap year, no real month length or year length consideration). But you can completely customize those factors. For example to deal with work time logs:

$cascades = CarbonInterval::getCascadeFactors(); // save initial factors

CarbonInterval::setCascadeFactors([
    'minute' => [60, 'seconds'],
    'hour' => [60, 'minutes'],
    'day' => [8, 'hours'],
    'week' => [5, 'days'],
    // in this example the cascade won't go farther than week unit
]);

echo CarbonInterval::fromString('20h')->cascade()->forHumans();              // 2 days 4 hours
echo CarbonInterval::fromString('10d')->cascade()->forHumans();              // 2 weeks
echo CarbonInterval::fromString('3w 18d 53h 159m')->cascade()->forHumans();  // 7 weeks 4 days 7 hours 39 minutes

// You can see currently set factors with getFactor:
echo CarbonInterval::getFactor('minutes', /* per */ 'hour');                 // 60
echo CarbonInterval::getFactor('days', 'week');                              // 5

// And common factors can be get with short-cut methods:
echo CarbonInterval::getDaysPerWeek();                                       // 5
echo CarbonInterval::getHoursPerDay();                                       // 8
echo CarbonInterval::getMinutesPerHour();                                    // 60
echo CarbonInterval::getSecondsPerMinute();                                  // 60
echo CarbonInterval::getMillisecondsPerSecond();                             // 1000
echo CarbonInterval::getMicrosecondsPerMillisecond();                        // 1000

CarbonInterval::setCascadeFactors($cascades); // restore original factors

Is it possible to convert an interval into a given unit (using provided cascade factors).

echo CarbonInterval::days(3)->addHours(5)->total('hours'); // 77
echo CarbonInterval::days(3)->addHours(5)->totalHours;     // 77
echo CarbonInterval::months(6)->totalWeeks;                // 24
echo CarbonInterval::year()->totalDays;                    // 336

->total method and properties need cascaded intervals, if your interval can have overflow, cascade them before calling these feature:

echo CarbonInterval::minutes(1200)->cascade()->total('hours'); // 20
echo CarbonInterval::minutes(1200)->cascade()->totalHours; // 20

You can also get the ISO 8601 spec of the inverval with spec()

echo CarbonInterval::days(3)->addHours(5)->spec(); // P3DT5H
// By default microseconds are trimmed (as they would fail to recreate a proper DateInterval)
echo CarbonInterval::days(3)->addSeconds(5)->addMicroseconds(987654)->spec(); // P3DT5S
// But you can explicitly add them:
echo CarbonInterval::days(3)->addSeconds(5)->addMicroseconds(987654)->spec(true); // P3DT5.987654S

It's also possible to get it from a DateInterval object since to the static helper:

echo CarbonInterval::getDateIntervalSpec(new DateInterval('P3DT6M10S')); // P3DT6M10S

List of date intervals can be sorted thanks to the compare() and compareDateIntervals() methods:

$halfDay = CarbonInterval::hours(12);
$oneDay = CarbonInterval::day();
$twoDay = CarbonInterval::days(2);

echo CarbonInterval::compareDateIntervals($oneDay, $oneDay);   // 0
echo $oneDay->compare($oneDay);                                // 0
echo CarbonInterval::compareDateIntervals($oneDay, $halfDay);  // 1
echo $oneDay->compare($halfDay);                               // 1
echo CarbonInterval::compareDateIntervals($oneDay, $twoDay);   // -1
echo $oneDay->compare($twoDay);                                // -1

$list = [$twoDay, $halfDay, $oneDay];
usort($list, ['Carbon\CarbonInterval', 'compareDateIntervals']);

echo implode(', ', $list);                                     // 12 hours, 1 day, 2 days

Alternatively to fixed intervals, Dynamic intervals can be described with a function to step from a date to an other date:

$weekDayInterval = new CarbonInterval(function (CarbonInterface $date, bool $negated): DateTime {
    // $negated is true when a subtraction is requested, false when an addition is requested
    return $negated
        ? $date->subWeekday()
        : $date->addWeekday();
});

echo Carbon::parse('Wednesday')->sub($weekDayInterval)->dayName; // Tuesday
echo "\n";
echo Carbon::parse('Friday')->add($weekDayInterval)->dayName; // Monday
echo "\n";

foreach (Carbon::parse('2020-06-01')->range('2020-06-17', $weekDayInterval) as $date) {
    // every week day
    echo ' '.$date->day;
}
// 1 2 3 4 5 8 9 10 11 12 15 16 17

You can access and modify the closure step definition using getStep() and setStep() (the setter can take null to remove it so it becomes a simple fixed interval. And as long as the interval has a step, it will take the precedence over all fixed units it contains.

You can call convertDate() to apply the current dynamic or static interval to a date (DateTime, Carbon or immutable ones) positively (or negatively passing true as a second argument):

echo $weekDayInterval->convertDate(new DateTime('Wednesday'), true)->dayName; // Tuesday
echo $weekDayInterval->convertDate(new DateTime('Friday'))->dayName; // Monday

Dump interval values as an array with:

$interval = CarbonInterval::months(2)->addHours(12)->addSeconds(50);

// All the values:
print_r($interval->toArray());
/*
Array
(
    [years] => 0
    [months] => 2
    [weeks] => 0
    [days] => 0
    [hours] => 12
    [minutes] => 0
    [seconds] => 50
    [microseconds] => 0
)

*/

// Values sequence from the biggest to the smallest non-zero ones:
print_r($interval->getValuesSequence());
/*
Array
(
    [months] => 2
    [weeks] => 0
    [days] => 0
    [hours] => 12
    [minutes] => 0
    [seconds] => 50
)

*/

// Non-zero values:
print_r($interval->getNonZeroValues());
/*
Array
(
    [months] => 2
    [hours] => 12
    [seconds] => 50
)

*/

Last, a CarbonInterval instance can be converted into a CarbonPeriod instance by calling toPeriod() with complementary arguments.

I hear you ask what is a CarbonPeriod instance. Oh! Perfect transition to our next chapter.

CarbonPeriod

CarbonPeriod is a human-friendly version of the DatePeriod with many shortcuts.

// Create a new instance:
$period = new CarbonPeriod('2018-04-21', '3 days', '2018-04-27');
// Use static constructor:
$period = CarbonPeriod::create('2018-04-21', '3 days', '2018-04-27');
// Use the fluent setters:
$period = CarbonPeriod::since('2018-04-21')->days(3)->until('2018-04-27');
// Start from a CarbonInterval:
$period = CarbonInterval::days(3)->toPeriod('2018-04-21', '2018-04-27');
// From a diff:
$period = Carbon::parse('2020-08-29')->diff('2020-09-02')->stepBy('day');
$period = Carbon::parse('2020-08-29')->diff('2020-09-02')->stepBy(12, 'hours');
// toPeriod can also be called from a Carbon or CarbonImmutable instance:
$period = Carbon::parse('2018-04-21')->toPeriod('2018-04-27', '3 days'); // pass end and interval
// interval can be a string, a DateInterval or a CarbonInterval
// You also can pass 2 arguments: number an string:
$period = Carbon::parse('2018-04-21')->toPeriod('2018-04-27', 3, 'days');
// Same as above:
$period = Carbon::parse('2018-04-21')->range('2018-04-27', 3, 'days'); // Carbon::range is an alias of Carbon::toPeriod
// Still the same:
$period = Carbon::parse('2018-04-21')->daysUntil('2018-04-27', 3);
// By default daysUntil will use a 1-day interval:
$period = Carbon::parse('2018-04-21')->daysUntil('2018-04-27'); // same as CarbonPeriod::create('2018-04-21', '1 day', '2018-04-27')
/*
    microsUntil() or microsecondsUntil() provide the same feature for microseconds intervals
    millisUntil() or millisecondsUntil() provide the same feature for milliseconds intervals
    secondsUntil() provides the same feature for seconds intervals
    minutesUntil() provides the same feature for minutes intervals
    hoursUntil() provides the same feature for hours intervals
    weeksUntil() provides the same feature for weeks intervals
    monthsUntil() provides the same feature for months intervals
    quartersUntil() provides the same feature for quarters intervals
    yearsUntil() provides the same feature for years intervals
    decadesUntil() provides the same feature for decades intervals
    centuriesUntil() provides the same feature for centuries intervals
    millenniaUntil() provides the same feature for millennia intervals
*/
// Using number of recurrences:
CarbonPeriod::create('now', '1 day', 3); // now, now + 1 day, now + 2 day
// Can be infinite:
CarbonPeriod::create('now', '2 days', INF); // infinite iteration
CarbonPeriod::create('now', '2 days', INF)->calculateEnd()->isEndOfTime(); // true
CarbonPeriod::create('now', CarbonInterval::days(-2), INF)->calculateEnd()->isStartOfTime(); // true

A CarbonPeriod can be constructed in a number of ways:

• start date, end date and optional interval (by default 1 day),
• start date, number of recurrences and optional interval,
• an ISO 8601 interval specification,
• from an other DatePeriod or CarbonPeriod using CarbonPeriod::instance($period) or simply using new CarbonPeriod($period).

Dates can be given as DateTime/Carbon instances, absolute strings like "2007-10-15 15:00" or relative strings, for example "next monday". Interval can be given as DateInterval/CarbonInterval instance, ISO 8601 interval specification like "P4D", or human readable string, for example "4 days".

Default constructor and create() methods are very forgiving in terms of argument types and order, so if you want to be more precise the fluent syntax is recommended. On the other hand you can pass dynamic array of values to createFromArray() which will do the job of constructing a new instance with the given array as a list of arguments.

CarbonPeriod implements the Iterator interface. It means that it can be passed directly to a foreach loop:

$period = CarbonPeriod::create('2018-04-21', '3 days', '2018-04-27');
foreach ($period as $key => $date) {
    if ($key) {
        echo ', ';
    }
    echo $date->format('m-d');
}
// 04-21, 04-24, 04-27
echo "\n";

// Here is what happens under the hood:
$period->rewind(); // restart the iteration
while ($period->valid()) { // check if current item is valid
    if ($period->key()) { // echo comma if current key is greater than 0
        echo ', ';
    }
    echo $period->current()->format('m-d'); // echo current date
    $period->next(); // move to the next item
}
// 04-21, 04-24, 04-27

Parameters can be modified during the iteration:

$period = CarbonPeriod::create('2018-04-29', 7);
$dates = [];
foreach ($period as $key => $date) {
    if ($key === 3) {
        $period->invert()->start($date); // invert() is an alias for invertDateInterval()
    }
    $dates[] = $date->format('m-d');
}

echo implode(', ', $dates); // 04-29, 04-30, 05-01, 05-02, 05-01, 04-30, 04-29

Just as DatePeriod, the CarbonPeriod supports ISO 8601 time interval specification.

Note that the native DatePeriod treats recurrences as a number of times to repeat the interval. Thus it will give one less result when the start date is excluded. Introduction of custom filters in CarbonPeriod made it even more difficult to know the number of results. For that reason we changed the implementation slightly, and recurrences are treated as an overall limit for number of returned dates.

// Possible options are: CarbonPeriod::EXCLUDE_START_DATE | CarbonPeriod::EXCLUDE_END_DATE
// Default value is 0 which will have the same effect as when no options are given.
$period = CarbonPeriod::createFromIso('R4/2012-07-01T00:00:00Z/P7D', CarbonPeriod::EXCLUDE_START_DATE);
$dates = [];
foreach ($period as $date) {
    $dates[] = $date->format('m-d');
}

echo implode(', ', $dates); // 07-08, 07-15, 07-22, 07-29

You can retrieve data from the period with variety of getters:

$period = CarbonPeriod::create('2010-05-06', '2010-05-25', CarbonPeriod::EXCLUDE_START_DATE);

$exclude = $period->getOptions() & CarbonPeriod::EXCLUDE_START_DATE;

echo $period->getStartDate();            // 2010-05-06 00:00:00
echo "\n";
echo $period->getEndDate();              // 2010-05-25 00:00:00
// Note than ->getEndDate() will return null when the end is not fixed.
// For example CarbonPeriod::since('2018-04-21')->times(3) use repetition, so we don't know the end before iteration.
// Then you can use ->calculateEnd() instead that will use getEndDate() if available and else will execute a complete
// iteration to calculate the end date.
echo "\n";
echo $period->getDateInterval();         // 1 day
echo "\n";
echo $exclude ? 'exclude' : 'include';   // exclude
echo "\n";

var_dump($period->isStartIncluded());    // bool(false)
echo "\n";
var_dump($period->isEndIncluded());      // bool(true)
echo "\n";
var_dump($period->isStartExcluded());    // bool(true)
echo "\n";
var_dump($period->isEndExcluded());      // bool(false)
echo "\n";

echo $period->getIncludedStartDate();    // 2010-05-07 00:00:00
// If start is included getIncludedStartDate() = getStartDate()
// If start is excluded getIncludedStartDate() = getStartDate() + 1 interval
echo "\n";
echo $period->getIncludedEndDate();      // 2010-05-25 00:00:00
// If end is included getIncludedEndDate() = getEndDate()
// If end is excluded getIncludedEndDate() = getEndDate() - 1 interval
// If end is null getIncludedEndDate() = calculateEnd(), it means the period is actually iterated to get the last date
echo "\n";

echo $period->toString();                // Every 1 day from 2010-05-06 to 2010-05-25
echo "\n";
echo $period; /*implicit toString*/      // Every 1 day from 2010-05-06 to 2010-05-25

Additional getters let you access the results as an array:

$period = CarbonPeriod::create('2010-05-11', '2010-05-13');

echo $period->count();                   // 3, equivalent to count($period)
echo "\n";
echo implode(', ', $period->toArray());  // 2010-05-11 00:00:00, 2010-05-12 00:00:00, 2010-05-13 00:00:00
echo "\n";
echo $period->first();                   // 2010-05-11 00:00:00
echo "\n";
echo $period->last();                    // 2010-05-13 00:00:00

Note that if you intend to work using the above functions it's a good idea to store the result of toArray() call to a variable and use it instead, because each call performs a full iteration internally.

To change the parameters you can use setter methods:

$period = CarbonPeriod::create('2010-05-01', '2010-05-14', CarbonPeriod::EXCLUDE_END_DATE);

$period->setStartDate('2010-05-11');
echo implode(', ', $period->toArray());  // 2010-05-11 00:00:00, 2010-05-12 00:00:00, 2010-05-13 00:00:00
echo "\n";

// Second argument can be optionally used to exclude the date from the results.
$period->setStartDate('2010-05-11', false);
$period->setEndDate('2010-05-14', true);
echo implode(', ', $period->toArray());  // 2010-05-12 00:00:00, 2010-05-13 00:00:00, 2010-05-14 00:00:00
echo "\n";

$period->setRecurrences(2);
echo implode(', ', $period->toArray());  // 2010-05-12 00:00:00, 2010-05-13 00:00:00
echo "\n";

$period->setDateInterval('PT12H');
echo implode(', ', $period->toArray());  // 2010-05-11 12:00:00, 2010-05-12 00:00:00

// This can also be set to 12 hours in all the following ways:
$period->setDateInterval('12h');
$period->setDateInterval('12 hours');
$period->setDateInterval(12, 'hours');
$period->setDateInterval(12, \Carbon\Unit::Hour);

// And reset to no explicit interval (will then use 1 day if iterated)
$period->resetDateInterval();

You can change options using setOptions() to replace all options but you also can change them separately:

$period = CarbonPeriod::create('2010-05-06', '2010-05-25');

var_dump($period->isStartExcluded());    // bool(false)
var_dump($period->isEndExcluded());      // bool(false)

$period->toggleOptions(CarbonPeriod::EXCLUDE_START_DATE, true); // true, false or nothing to invert the option
var_dump($period->isStartExcluded());    // bool(true)
var_dump($period->isEndExcluded());      // bool(false) (unchanged)

$period->excludeEndDate();               // specify false to include, true or omit to exclude
var_dump($period->isStartExcluded());    // bool(true) (unchanged)
var_dump($period->isEndExcluded());      // bool(true)

$period->excludeStartDate(false);        // specify false to include, true or omit to exclude
var_dump($period->isStartExcluded());    // bool(false)
var_dump($period->isEndExcluded());      // bool(true)

You can check 2 periods overlap or not:

$period = CarbonPeriod::create('2010-05-06', '2010-05-25');
$period2 = CarbonPeriod::create('2010-05-22', '2010-05-24');

var_dump($period->overlaps('2010-05-22', '2010-06-03'));   // bool(true)
var_dump($period->overlaps($period2));                     // bool(true)

$period = CarbonPeriod::create('2010-05-06 12:00', '2010-05-25');
$start = Carbon::create('2010-05-06 05:00');
$end = Carbon::create('2010-05-06 11:59');
var_dump($period->overlaps($start, $end));                 // bool(false)

As mentioned earlier, per ISO 8601 specification, recurrences is a number of times the interval should be repeated. The native DatePeriod will thus vary the number of returned dates depending on the exclusion of the start date. Meanwhile, CarbonPeriod being more forgiving in terms of input and allowing custom filters, treats recurrences as an overall limit for number of returned dates:

$period = CarbonPeriod::createFromIso('R4/2012-07-01T00:00:00Z/P7D');
$days = [];
foreach ($period as $date) {
    $days[] = $date->format('d');
}

echo $period->getRecurrences();          // 4
echo implode(', ', $days);               // 01, 08, 15, 22

$days = [];
$period->setRecurrences(3)->excludeStartDate();
foreach ($period as $date) {
    $days[] = $date->format('d');
}

echo $period->getRecurrences();          // 3
echo implode(', ', $days);               // 08, 15, 22

$days = [];
$period = CarbonPeriod::recurrences(3)->sinceNow();
foreach ($period as $date) {
    $days[] = $date->format('Y-m-d');
}

echo implode(', ', $days);               // 2025-07-05, 2025-07-06, 2025-07-07

Dates returned by the DatePeriod can be easily filtered. Filters can be used for example to skip certain dates or iterate only over working days or weekends. A filter function should return true to accept a date, false to skip it but continue searching or CarbonPeriod::END_ITERATION to end the iteration.

$period = CarbonPeriod::between('2000-01-01', '2000-01-15');
$weekendFilter = function ($date) {
    return $date->isWeekend();
};
$period->filter($weekendFilter);

$days = [];
foreach ($period as $date) {
    $days[] = $date->format('m-d');
}
echo implode(', ', $days);                         // 01-01, 01-02, 01-08, 01-09, 01-15

You also can skip one or more value(s) inside the loop.

$period = CarbonPeriod::between('2000-01-01', '2000-01-10');
$days = [];
foreach ($period as $date) {
    $day = $date->format('m-d');
    $days[] = $day;
    if ($day === '01-04') {
        $period->skip(3);
    }
}
echo implode(', ', $days);                         // 01-01, 01-02, 01-03, 01-04, 01-08, 01-09, 01-10

getFilters() allow you to retrieve all the stored filters in a period. But be aware the recurrences limit and the end date will appear in the returned array as they are stored internally as filters.

$period = CarbonPeriod::end('2000-01-01')->recurrences(3);
var_export($period->getFilters());
/*
array (
  0 => 
  array (
    0 => 
    array (
      0 => 'Carbon\\CarbonPeriod',
      1 => 'filterEndDate',
    ),
    1 => NULL,
  ),
  1 => 
  array (
    0 => 
    array (
      0 => 'Carbon\\CarbonPeriod',
      1 => 'filterRecurrences',
    ),
    1 => NULL,
  ),
)
*/

Filters are stored in a stack and can be managed using a special set of methods:

$period = CarbonPeriod::between('2000-01-01', '2000-01-15');
$weekendFilter = function ($date) {
    return $date->isWeekend();
};

var_dump($period->hasFilter($weekendFilter));      // bool(false)
$period->addFilter($weekendFilter);
var_dump($period->hasFilter($weekendFilter));      // bool(true)
$period->removeFilter($weekendFilter);
var_dump($period->hasFilter($weekendFilter));      // bool(false)

// To avoid storing filters as variables you can name your filters:
$period->prependFilter(function ($date) {
    return $date->isWeekend();
}, 'weekend');

var_dump($period->hasFilter('weekend'));           // bool(true)
$period->removeFilter('weekend');
var_dump($period->hasFilter('weekend'));           // bool(false)

Order in which filters are added can have an impact on the performance and on the result, so you can use addFilter() to add a filter in the end of stack; and you can use prependFilter() to add one at the beginning. You can even use setFilters() to replace all filters. Note that you'll have to keep correct format of the stack and remember about internal filters for recurrences limit and end date. Alternatively you can use resetFilters() method and then add new filters one by one.

For example, when you add a custom filter that limits the number of attempted dates, the result will be different if you add it before or after the weekday filter.

// Note that you can pass a name of any Carbon method starting with "is", including macros
$period = CarbonPeriod::between('2018-05-03', '2018-05-25')->filter('isWeekday');

$attempts = 0;
$attemptsFilter = function () use (&$attempts) {
    return ++$attempts <= 5 ? true : CarbonPeriod::END_ITERATION;
};

$period->prependFilter($attemptsFilter, 'attempts');
$days = [];
foreach ($period as $date) {
    $days[] = $date->format('m-d');
}
echo implode(', ', $days);                         // 05-03, 05-04, 05-07

$attempts = 0;

$period->removeFilter($attemptsFilter)->addFilter($attemptsFilter, 'attempts');
$days = [];
foreach ($period as $date) {
    $days[] = $date->format('m-d');
}
echo implode(', ', $days);                         // 05-03, 05-04, 05-07, 05-08, 05-09

Note that the built-in recurrences filter doesn't work this way. It is instead based on the current key which is incremented only once per item, no matter how many dates have to be checked before a valid date is found. This trick makes it work the same both if you put it at the beginning or at the end of the stack.

A number of aliases has been added to simplify building the CarbonPeriod:

// "start", "since", "sinceNow":
CarbonPeriod::start('2017-03-10') == CarbonPeriod::create()->setStartDate('2017-03-10');
// Same with optional boolean argument $inclusive to change the option about include/exclude start date:
CarbonPeriod::start('2017-03-10', true) == CarbonPeriod::create()->setStartDate('2017-03-10', true);
// "end", "until", "untilNow":
CarbonPeriod::end('2017-03-20') == CarbonPeriod::create()->setEndDate('2017-03-20');
// Same with optional boolean argument $inclusive to change the option about include/exclude end date:
CarbonPeriod::end('2017-03-20', true) == CarbonPeriod::create()->setEndDate('2017-03-20', true);
// "dates", "between":
CarbonPeriod::dates(..., ...) == CarbonPeriod::create()->setDates(..., ...);
// "recurrences", "times":
CarbonPeriod::recurrences(5) == CarbonPeriod::create()->setRecurrences(5);
// "options":
CarbonPeriod::options(...) == CarbonPeriod::create()->setOptions(...);
// "toggle":
CarbonPeriod::toggle(..., true) == CarbonPeriod::create()->toggleOptions(..., true);
// "filter", "push":
CarbonPeriod::filter(...) == CarbonPeriod::create()->addFilter(...);
// "prepend":
CarbonPeriod::prepend(...) == CarbonPeriod::create()->prependFilter(...);
// "filters":
CarbonPeriod::filters(...) == CarbonPeriod::create()->setFilters(...);
// "interval", "each", "every", "step", "stepBy":
CarbonPeriod::interval(...) == CarbonPeriod::create()->setDateInterval(...);
// "invert":
CarbonPeriod::invert() == CarbonPeriod::create()->invertDateInterval();
// "year", "months", "month", "weeks", "week", "days", "dayz", "day",
// "hours", "hour", "minutes", "minute", "seconds", "second":
CarbonPeriod::hours(5) == CarbonPeriod::create()->setDateInterval(CarbonInterval::hours(5));

CarbonPeriod can be easily converted to a human-readable string and ISO 8601 specification:

$period = CarbonPeriod::create('2000-01-01 12:00', '3 days 12 hours', '2000-01-15 12:00');
echo $period->toString();            // Every 3 days and 12 hours from 2000-01-01 12:00:00 to 2000-01-15 12:00:00
echo "\n";
echo $period->toIso8601String();     // 2000-01-01T12:00:00+00:00/P3DT12H/2000-01-15T12:00:00+00:00

Period use and return Carbon instance by default, but you can easily set/get the date class to use in order to get immutable dates for example or any class implementing CarbonInterface.

$period = new CarbonPeriod;
$period->setDateClass(CarbonImmutable::class);
$period->every('3 days 12 hours')->since('2000-01-01 12:00')->until('2000-01-15 12:00');

echo $period->getDateClass();              // Carbon\CarbonImmutable
echo "\n";
echo $period->getStartDate();              // 2000-01-01 12:00:00
echo "\n";
echo get_class($period->getStartDate());   // Carbon\CarbonImmutable

CarbonPeriod has forEach() and map() helper methods:

$period = CarbonPeriod::create('2018-04-21', '3 days', '2018-04-27');
$dates = $period->map(function (Carbon $date) {
    return $date->format('m-d');
});
// Or with PHP 7.4:
// $dates = $period->map(fn(Carbon $date) => $date->format('m-d'));
$array = iterator_to_array($dates); // $dates is a iterable \Generator
var_dump($array);
echo implode(', ', $array);
/*
array(3) {
  [0]=>
  string(5) "04-21"
  [1]=>
  string(5) "04-24"
  [2]=>
  string(5) "04-27"
}
04-21, 04-24, 04-27
*/
echo "\n";

// Here is what happens under the hood:
$period->forEach(function (Carbon $date) {
    echo $date->format('m-d')."\n";
});
/*
04-21
04-24
04-27
*/

As all other Carbon classes, CarbonPeriod has a cast() method to convert it:

$period = CarbonPeriod::create('2000-01-01 12:00', '3 days 12 hours', '2000-01-15 12:00');

// It would also works if your class extends DatePeriod
class MyPeriod extends CarbonPeriod {}

echo get_class($period->cast(MyPeriod::class)); // MyPeriod

// Shortcut to export as raw DatePeriod:
echo get_class($period->toDatePeriod());   // DatePeriod

You can check if periods follow themselves. Period A follows period B if the first iteration date of B equals to the last iteration date of A + the interval of A. For example [2019-02-01 => 2019-02-16] follows [2019-01-15 => 2019-01-31] (assuming neither start nor end are excluded via option for those period and assuming those period as a (1 day)-interval.

$a = CarbonPeriod::create('2019-01-15', '2019-01-31');
$b = CarbonPeriod::create('2019-02-01', '2019-02-16');

var_dump($b->follows($a));               // bool(true)
var_dump($a->isFollowedBy($b));          // bool(true)
// ->isConsecutiveWith($period) is true if it either ->follows($period) or ->isFollowedBy($period)
var_dump($b->isConsecutiveWith($a));     // bool(true)
var_dump($a->isConsecutiveWith($b));     // bool(true)

The contains() method allow you to check if a date is in the period range.

$period = CarbonPeriod::create('2019-01-15', '2019-01-31');

var_dump($period->contains('2019-01-22'));         // bool(true)

The comparison includes start and end unless you excluded them in the option and as for it concerns contains(), the exclusion only exclude the exact date, so:

$period = CarbonPeriod::create('2019-01-15', '2019-01-31', CarbonPeriod::EXCLUDE_END_DATE);

var_dump($period->contains('2019-01-31 00:00:00')); // bool(false)
var_dump($period->contains('2019-01-30 23:59:59')); // bool(true)

You can use start/end comparisons methods (that ignore exclusions) for more precise comparisons:

• startsAt() start == date
• startsBefore() start < date
• startsBeforeOrAt() start <= date
• startsAfter() start > date
• startsAfterOrAt() start >= date
• endsAt() end == date
• endsBefore() end < date
• endsBeforeOrAt() end <= date
• endsAfter() end > date
• endsAfterOrAt() end >= date
• isStarted() start <= now
• isEnded() end <= now
• isInProgress() started but not ended

CarbonTimeZone

Starting with Carbon 2, timezones are now handled with a dedicated class CarbonTimeZone extending DateTimeZone.

$tz = new CarbonTimeZone('Europe/Zurich'); // instance way
$tz = CarbonTimeZone::create('Europe/Zurich'); // static way

// Get the original name of the timezone (can be region name or offset string):
echo $tz->getName();                 // Europe/Zurich
echo "\n";
// Casting a CarbonTimeZone to string will automatically call getName:
echo $tz;                            // Europe/Zurich
echo "\n";
echo $tz->getAbbreviatedName();      // CET
echo "\n";
// With DST on:
echo $tz->getAbbreviatedName(true);  // CEST
echo "\n";
// Alias of getAbbreviatedName:
echo $tz->getAbbr();                 // CET
echo "\n";
echo $tz->getAbbr(true);             // CEST
echo "\n";
// toRegionName returns the first matching region or false, if timezone was created with a region name,
// it will simply return this initial value.
echo $tz->toRegionName();            // Europe/Zurich
echo "\n";
// toOffsetName will give the current offset string for this timezone:
echo $tz->toOffsetName();            // +02:00
echo "\n";
// As with DST, this offset can change depending on the date, you may pass a date argument to specify it:
$winter = Carbon::parse('2018-01-01');
echo $tz->toOffsetName($winter);     // +01:00
echo "\n";
$summer = Carbon::parse('2018-07-01');
echo $tz->toOffsetName($summer);     // +02:00

The default timezone is given by date_default_timezone_get so it will be driven by the INI settings date.timezone but you really should override it at application level using date_default_timezone_set and you should set it to "UTC", if you're temped to or already use an other timezone as default, please read the following article: Always Use UTC Dates And Times.

It explains why UTC is a reliable standard. And this best-practice is even more important in PHP because the PHP DateTime API has many bugs with offsets changes and DST timezones. Some of them appeared on minor versions and even on patch versions (so you can get different results running the same code on PHP 7.1.7 and 7.1.8 for example) and some bugs are not even fixed yet. So we highly recommend to use UTC everywhere and only change the timezone when you want to display a date. See our first macro example.

While, region timezone ("Continent/City") can have DST and so have variable offset during the year, offset timezone have constant fixed offset:

$tz = CarbonTimeZone::create('+03:00'); // full string
$tz = CarbonTimeZone::create(3); // or hour integer short way

$tz = CarbonTimeZone::createFromHourOffset(3); // explicit method rather type-based detection is even better
$tz = CarbonTimeZone::createFromMinuteOffset(180); // the equivalent in minute unit

// Both above rely on the static minute-to-string offset converter also available as:
$tzString = CarbonTimeZone::getOffsetNameFromMinuteOffset(180);
$tz = CarbonTimeZone::create($tzString);

echo $tz->getName();                 // +03:00
echo "\n";
echo $tz;                            // +03:00
echo "\n";
// toRegionName will try to guess what region it could be:
echo $tz->toRegionName();            // Europe/Helsinki
echo "\n";
// to guess with DST off:
echo $tz->toRegionName(null, 0);     // Europe/Moscow
echo "\n";
// toOffsetName will give the initial offset no matter the date:
echo $tz->toOffsetName();            // +03:00
echo "\n";
echo $tz->toOffsetName($winter);     // +03:00
echo "\n";
echo $tz->toOffsetName($summer);     // +03:00

You also can convert region timezones to offset timezones and reciprocally.

$tz = new CarbonTimeZone(7);

echo $tz;                            // +07:00
echo "\n";
$tz = $tz->toRegionTimeZone();
echo $tz;                            // Asia/Novosibirsk
echo "\n";
$tz = $tz->toOffsetTimeZone();
echo $tz;                            // +07:00

You can create a CarbonTimeZone from mixed values using instance() method.

$tz = CarbonTimeZone::instance(new DateTimeZone('Europe/Paris'));

echo $tz;                            // Europe/Paris
echo "\n";

// Bad timezone will throw an exception
try {
    CarbonTimeZone::instance('Europe/Chicago');
} catch (InvalidArgumentException $exception) {
    $error = $exception->getMessage();
}
echo $error;                         // Unknown or bad timezone (Europe/Chicago)

// as some value cannot be dump as string in an error message or
// have unclear dump, you may pass a second argument to display
// instead in the errors
try {
    $continent = 'Europe';
    $city = 'Chicago';
    $mixedValue = ['continent' => $continent, 'city' => $city];
    CarbonTimeZone::instance("$continent/$city", json_encode($mixedValue));
} catch (InvalidArgumentException $exception) {
    $error = $exception->getMessage();
}
echo $error;                         // Unknown or bad timezone ({"continent":"Europe","city":"Chicago"})

The same way, Carbon::create() return false if you pass an incorrect value (such as a negative month) but it throws an exception in strict mode. Carbon::createStrict() is like create() but throws an exception even if not in strict mode.

Migrate to Carbon 3

If you plan to migrate from Carbon 2 to Carbon 3, please note the following breaking changes you should take care of.

createFromTimestamp UTC by default

Timezone for createFromTimestamp was previously date_default_timezone_get() in Carbon 2.

In Carbon 3, it's now "UTC" so to be consistent with DateTime behavior when doing new DateTime('@123').

Those who use UTC as default timezone will not be impacted. As a reminder we strongly recommend this setup. See timezone section

We also recommend to always call createFromTimestamp with 2 parameters (i.e. explicitly pass a timezone) or to use createFromTimestampUTC().

diffIn*

Yes, the most impactful change is in diffIn* methods. They were returning positive integer by default, they will now return float:

$after = Carbon::now()->addSeconds(2);
$before = Carbon::now();

var_dump($after->diffInSeconds($before));

This was: int(1) in Carbon 2

This is: double(-1.999508) in Carbon 3

In Carbon 3, using (int) $after->diffInSeconds($before, true) or (int) abs($after->diffInSeconds($before)) allows to get explicitly an absolute and truncated value, so the same result as in v2.

Strong typing

Strong typing added in many method parameters will disallow so usages that was never meant to be supported such as bool or null in comparison methods.

In Carbon v2 the following return arbitrary results (despite it emits E_USER_DEPRECATED notices):

var_dump($date->eq(false)); // false
var_dump($date->gte(false)); // true
var_dump($date->gt(false)); // true
var_dump($date->eq(null)); // false
var_dump($date->gte(null)); // true
var_dump($date->gt(null)); // true

In Carbon v3, PHPDoc is moving to real types so any of this will throw a TypeError, it expects DateTimeInterface or string to be passed.

falsable => nullable

create, createFromFormat , createFromIsoFormat, createFromLocaleFormat and createFromLocaleIsoFormat returned Carbon|false, it's now Carbon|null (unlocking ?-> chaining and ?? throw error handling).

Removal of some deprecated methods

setUtf8 are formatLocalized removed. formatLocalized depends on OS language package and relies on setlocale() + strftime() (the last will be removed from PHP itself). ->isoFormat() should be used instead which is embedded translation files (so one can rely on getting the same translation everywhere) and is linked to Carbon locale (The current object locale that can be set with $date->locale('de') or if not set, the global one that Laravel is already setting using Carbon::setLocale('de')). And setUtf8 is no longer needed since formatLocalized is the only method that possibly had non-UTF-8 output.

setWeekStartsAt and setWeekEndsAt are also removed. You should either specify the day explictly when calling startOfWeek, for instance: ->startOfWeek(\Carbon\WeekDay::Wednesday) or change the locale appriopriately, for instance ->locale('en_US')->startOfWeek() goes to Sunday, while ->locale('en_GB')->startOfWeek() goes to Monday, ar_EG locale sets it to Saturday, etc.

Note that you can also create custom locales with a different start of week:

\Carbon\Translator::get('en_US@Cinema')->setTranslations([
    'first_day_of_week' => Carbon::FRIDAY,
]);

\Carbon\Translator::get('fr_FR@Cinema')->setTranslations([
    'first_day_of_week' => Carbon::WEDNESDAY,
]);

echo CarbonImmutable::now()->locale('fr_FR')->startOfWeek()->dayName;        // lundi
echo CarbonImmutable::now()->locale('fr_FR@Cinema')->startOfWeek()->dayName; // mercredi
echo CarbonImmutable::now()->locale('en_US')->startOfWeek()->dayName;        // Sunday
echo CarbonImmutable::now()->locale('en_US@Cinema')->startOfWeek()->dayName; // Friday

Strict timezone

All named argument tz: have been replaced with timezone: for explicitness and consistency with DateTime methods.

It's no longer possible to create a CarbonTimeZone object with 0 arguments, the name is now mandatory to construct it.

Creating timezone with a bad/unknown name will now always throw an exception, it's no longer possible to mute them by disabling strict-mode.

Immutable start and end properties of CarbonPeriod

CarbonPeriod now extends DatePeriod so it can now conveniently substitute it anywhere a DatePeriod is expected. However, it also inherits the constraint that ->start and ->end are immutable properties. We recommend that you use CarbonPeriodImmutable which will then be fully compatible (its properties including start and end cannot be modified); while CarbonPeriod has setters ->setStartDate() and ->setEndDate() that will actually modify from when to when the period iterates and also the value you can retrieve using ->getStartDate() and ->getEndDate(), however ->start and ->end will still contain initial start and end and not the new values after modification.

isSame*

Since Carbon 3, it's no longer allowed to call isSame* methods (such as isSameDay, isSameMonth without parameters. You need to explictly pass a date (string or DateTime object) so it's a comparison between 2: $a->isSameHour($b), in Carbon 2, it was by default using "now" as default value, now you should tell it explictly if you mean it: $a->isSameHour('now') or you can use ->isCurrent* methods instead: $a->isCurrentHour()

Dropped maxValue() and minValue()

Since Carbon 3, Carbon::minValue() and Carbon::maxValue() have been removed, use CarbonImmutable::startOfTime() and CarbonImmutable::endOfTime() instead. While the old methods depended on the system and were available on mutable objects, the new ones are arbitrary dates 0001-01-01 00:00:00 and 9999-12-31 23:59:59.999999 only available on CarbonImmutable, and you can check a date is at such end using ->isStartOfTime() and ->isEndOfTime().

Migrate to Carbon 2

If you plan to migrate from Carbon 1 to Carbon 2, please note the following breaking changes you should take care of.

• Default values (when parameters are omitted) for $month and $day in the ::create() method are now 1 (were values from current date in Carbon 1). And default values for $hour, $minute and $second are now 0, this goes for omitted values, but you still can pass explicitly null to get the current value from now (similar behavior as in Carbon 1).
• Now you get microsecond precision everywhere, it also means 2 dates in the same second but not in the same microsecond are no longer equal.
• $date->jsonSerialize() and json_encode($date) no longer returns arrays but simple strings: "2017-06-27T13:14:15.000000Z". This allows to create dates from it easier in JavaScript. You still can get the previous behavior using:

  Carbon::serializeUsing(function ($date) {
      return [
          'date' => $date->toDateTimeString(),
      ] + (array) $date->tz;
  });

• $date->setToStringFormat() with a closure no longer return a format but a final string. So you can return any string and the following in Carbon 1:

  Carbon::setToStringFormat(function ($date) {
      return $date->year === 1976 ?
          'jS \o\f F g:i:s a' :
          'jS \o\f F, Y g:i:s a';
  });

  would become in Carbon 2:

  Carbon::setToStringFormat(function ($date) {
      return $date->formatLocalized($date->year === 1976 ?
          'jS \o\f F g:i:s a' :
          'jS \o\f F, Y g:i:s a'
      );
  });

• setWeekStartsAt and setWeekEndsAt no longer throw exceptions on values out of ranges, but they are also deprecated.
• isSameMonth and isCurrentMonth now returns false for same month in different year but you can pass false as a second parameter of isSameMonth or first parameter of isCurrentMonth to compare ignoring the year.
• ::compareYearWithMonth() and ::compareYearWithMonth() have been removed. Strict comparisons are now the default. And you can use the next parameter of isSame/isCurrent set to false to get month-only comparisons.
• As we dropped PHP 5, $self is no longer needed in mixins you should just use $this instead.
• As PHP 7.1+ perfectly supports microseconds, useMicrosecondsFallback and isMicrosecondsFallbackEnabled are no longer needed and so have been removed.
• In Carbon 1, calls of an unknown method on CarbonInterval (ex: CarbonInterval::anything()) just returned null. In Carbon 2 they throw an exception.
• In Carbon 1, dayOfYear started from 0. In Carbon 2 it starts from 1.
• In Carbon 1, null was considered as 0 when passed to add/sub method (such as addDays(null), subMonths(null), etc.). In Carbon 2, it behaves the same as no parameters so default to 1. Anyway, you're discouraged to pass null in such methods as it's ambiguous and the behavior for next major version is not guaranteed.
• That's all folks! Every other methods you used in Carbon 1 should continue to work just the same with Carbon 2.