DateInterval::createFromDateString

(PHP 5 >= 5.3.0, PHP 7, PHP 8)

DateInterval::createFromDateString — Sets up a DateInterval from the relative parts of the string

Description

Object-oriented style

public static function DateInterval::createFromDateString(string $datetime): DateInterval

Procedural style

function date_interval_create_from_date_string(string $datetime): DateInterval|false

Uses the date/time parsers as used in the DateTimeImmutable constructor to create a DateInterval from the relative parts of the parsed string.

Parameters

datetime

A date with relative parts. Specifically, the relative formats supported by the parser used for DateTimeImmutable, DateTime, and strtotime() will be used to construct the DateInterval.

To use an ISO-8601 format string like P7D, you must use the DateInterval::__construct().

Return Values

Returns DateInterval on success. Procedural style returns false on failure.

Errors/Exceptions

Object Oriented API only: If an invalid Date/Time string is passed, DateMalformedIntervalStringException is thrown.

Changelog

Version	Description
8.4.0	Now has a tentative return type of DateInterval. Previously it was DateInterval\|false.
8.3.0	DateInterval::createFromDateString() now throws DateMalformedIntervalStringException if an invalid string is passed. Previously, it returned `false`, and a warning was emitted. date_interval_create_from_date_string() has not been changed.
8.2.0	Only the `from_string` and `date_string` properties will be visible when a DateInterval is created with this method.

Examples

Example #1 Parsing valid date intervals

<?php
// Each set of intervals is equal.
$i = new DateInterval('P1D');
$i = DateInterval::createFromDateString('1 day');

$i = new DateInterval('P2W');
$i = DateInterval::createFromDateString('2 weeks');

$i = new DateInterval('P3M');
$i = DateInterval::createFromDateString('3 months');

$i = new DateInterval('P4Y');
$i = DateInterval::createFromDateString('4 years');

$i = new DateInterval('P1Y1D');
$i = DateInterval::createFromDateString('1 year + 1 day');

$i = new DateInterval('P1DT12H');
$i = DateInterval::createFromDateString('1 day + 12 hours');

$i = new DateInterval('PT3600S');
$i = DateInterval::createFromDateString('3600 seconds');

Example #2 Parsing combinations and negative intervals

<?php
$i = DateInterval::createFromDateString('62 weeks + 1 day + 2 weeks + 2 hours + 70 minutes');
echo $i->format('%d %h %i'), "\n";

$i = DateInterval::createFromDateString('1 year - 10 days');
echo $i->format('%y %d'), "\n";

The above example will output:

449 2 70
1 -10

Example #3 Parsing special relative date intervals

<?php
$i = DateInterval::createFromDateString('last day of next month');
var_dump($i);

$i = DateInterval::createFromDateString('last weekday');
var_dump($i);

Output of the above example in PHP 8.2:

object(DateInterval)#1 (2) {
  ["from_string"]=>
  bool(true)
  ["date_string"]=>
  string(22) "last day of next month"
}
object(DateInterval)#2 (2) {
  ["from_string"]=>
  bool(true)
  ["date_string"]=>
  string(12) "last weekday"
}

Output of the above example in PHP 8 is similar to:

object(DateInterval)#1 (16) {
  ["y"]=>
  int(0)
  ["m"]=>
  int(1)
  ["d"]=>
  int(0)
  ["h"]=>
  int(0)
  ["i"]=>
  int(0)
  ["s"]=>
  int(0)
  ["f"]=>
  float(0)
  ["weekday"]=>
  int(0)
  ["weekday_behavior"]=>
  int(0)
  ["first_last_day_of"]=>
  int(2)
  ["invert"]=>
  int(0)
  ["days"]=>
  bool(false)
  ["special_type"]=>
  int(0)
  ["special_amount"]=>
  int(0)
  ["have_weekday_relative"]=>
  int(0)
  ["have_special_relative"]=>
  int(0)
}
object(DateInterval)#2 (16) {
  ["y"]=>
  int(0)
  ["m"]=>
  int(0)
  ["d"]=>
  int(0)
  ["h"]=>
  int(0)
  ["i"]=>
  int(0)
  ["s"]=>
  int(0)
  ["f"]=>
  float(0)
  ["weekday"]=>
  int(0)
  ["weekday_behavior"]=>
  int(0)
  ["first_last_day_of"]=>
  int(0)
  ["invert"]=>
  int(0)
  ["days"]=>
  bool(false)
  ["special_type"]=>
  int(1)
  ["special_amount"]=>
  int(-1)
  ["have_weekday_relative"]=>
  int(0)
  ["have_special_relative"]=>
  int(1)
}

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User Contributed Notes 2 notes

down

felix dot edelmann at check24 dot de ¶

1 year ago

Please note that Daylight Saving Time (DST) transitions only work as expected when using new \DateInterval(), not \DateInterval::createFromDateString().

<?php
$now = new \DateTimeImmutable("2025-03-29 13:00:00", new DateTimeZone('Europe/Berlin'));
var_dump($now);
// 2025-03-29 13:00:00

var_dump($now->add(\DateInterval::createFromDateString('1440 minutes')));
// 2025-03-30 13:00:00
var_dump($now->add(new \DateInterval('PT1440M')));
// 2025-03-30 14:00:00

// these are not equivalent:
var_dump(\DateInterval::createFromDateString('1440 minutes'));
var_dump(new \DateInterval('PT1440M'));
?>

down

daniel at justathought dot dev ¶

1 hour ago

This builds on [felix dot edelmann at check24 dot de]'s note about Daylight Saving Time (DST) transitions.

TLDR: it seems that **using the time component of an ISO duration** string is what switches-on time-zone awareness.  At least in this case, "*duration* string" may understate its meaning/effect.

Expand on Felix's code a little and a pattern starts to emerge:

<?php

$timeZone = new DateTimeZone('Europe/Berlin');

$beforeChangeover = new DateTimeImmutable('2025-03-29 13:00:00', $timeZone);

// To recap:

print_r($beforeChangeover->add(new DateInterval('P1D')));                            // => 2025-03-30 13:00
print_r($beforeChangeover->add(new DateInterval('PT1440M')));                        // => 2025-03-30 14:00 (+1 hour!)
print_r($beforeChangeover->add(new DateInterval('PT24H')));                          // => 2025-03-30 14:00 (+1 hour!)

print_r($beforeChangeover->add(DateInterval::createFromDateString('1 day')));        // => 2025-03-30 13:00
print_r($beforeChangeover->add(DateInterval::createFromDateString('1440 minute')));  // => 2025-03-30 13:00
print_r($beforeChangeover->add(DateInterval::createFromDateString('24 hour')));      // => 2025-03-30 13:00

print_r($beforeChangeover->modify('+1 day'));                                        // => 2025-03-30 13:00
print_r($beforeChangeover->modify('+1440 minute'));                                  // => 2025-03-30 13:00
print_r($beforeChangeover->modify('+24 hour'));                                      // => 2025-03-30 13:00

// diff():

print_r(new DateTimeImmutable('2025-03-30 13:00:00', $timeZone)->diff($beforeChangeover));  // => 1d 0h
print_r(new DateTimeImmutable('2025-03-30 14:00:00', $timeZone)->diff($beforeChangeover));  // => 1d 1h
?>

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