Please note, add() works a litte different than for DateTime-Objects.
Since DateTimeImmutable is in fact immutable. A line like this will not work:
$di = new DateTimeImmutable("2018-12-12T10:00:00");
$di->add(new DateInterval('PT45M')); // $di unchanged !!!
compared to
$dt = new DateTime("2018-12-12T10:00:00");
$dt->add(new DateInterval('PT45M')); // added 45 minutes
so you need to write
$di = new DateTimeImmutable("2018-12-12T10:00:00");
$di = $di->add(new DateInterval('PT45M')); // $di now changed
DateTimeImmutable::add
(PHP 5 >= 5.5.0, PHP 7, PHP 8)
DateTimeImmutable::add — Returns a new object, with added amount of days, months, years, hours, minutes and seconds
Description
Creates a new DateTimeImmutable object, and adds the specified DateInterval object to this, to represent the new value.
Parameters
-
interval -
A DateInterval object
Return Values
Returns a new DateTimeImmutable object with the modified data.
Examples
Example #1 DateTimeImmutable::add() example
Object-oriented style
<?php
$date = new DateTimeImmutable('2000-01-01');
$newDate = $date->add(new DateInterval('P10D'));
echo $newDate->format('Y-m-d') . "\n";
?>Example #2 Further DateTimeImmutable::add() examples
<?php
$date = new DateTimeImmutable('2000-01-01');
$newDate = $date->add(new DateInterval('PT10H30S'));
echo $newDate->format('Y-m-d H:i:s') . "\n";
$date = new DateTimeImmutable('2000-01-01');
$newDate = $date->add(new DateInterval('P7Y5M4DT4H3M2S'));
echo $newDate->format('Y-m-d H:i:s') . "\n";
?>The above example will output:
2000-01-01 10:00:30 2007-06-05 04:03:02
Example #3 Beware when adding months
<?php
$date = new DateTimeImmutable('2000-12-31');
$interval = new DateInterval('P1M');
$newDate1 = $date->add($interval);
echo $newDate1->format('Y-m-d') . "\n";
$newDate2 = $newDate1->add($interval);
echo $newDate2->format('Y-m-d') . "\n";
?>The above example will output:
2001-01-31 2001-03-03
See Also
- DateTimeImmutable::sub() - Subtracts an amount of days, months, years, hours, minutes and seconds
- DateTimeImmutable::diff() - Returns the difference between two DateTime objects
- DateTimeImmutable::modify() - Creates a new object with modified timestamp
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User Contributed Notes 1 note
Gunnar Bernstein ¶
5 years ago
