DateTime::modify

date_modify

(PHP 5 >= 5.2.0, PHP 7, PHP 8)

DateTime::modify -- date_modify — Alters the timestamp

Description

Object-oriented style

public DateTime::modify(string $modifier): DateTime|false

Procedural style

date_modify(DateTime $object, string $modifier): DateTime|false

Alter the timestamp of a DateTime object by incrementing or decrementing in a format accepted by DateTimeImmutable::__construct().

Parameters

object

Procedural style only: A DateTime object returned by date_create(). The function modifies this object.

modifier

A date/time string. Valid formats are explained in Date and Time Formats.

Return Values

Returns the DateTime object for method chaining or false on failure.

Examples

Example #1 DateTime::modify() example

Object-oriented style

<?php
$date = new DateTime('2006-12-12');
$date->modify('+1 day');
echo $date->format('Y-m-d');
?>

Procedural style

<?php
$date = date_create('2006-12-12');
date_modify($date, '+1 day');
echo date_format($date, 'Y-m-d');
?>

The above examples will output:

2006-12-13

Example #2 Beware when adding or subtracting months

<?php
$date = new DateTime('2000-12-31');

$date->modify('+1 month');
echo $date->format('Y-m-d') . "\n";

$date->modify('+1 month');
echo $date->format('Y-m-d') . "\n";
?>

The above example will output:

2001-01-31
2001-03-03

See Also