DateTime
PHP Manual

DateTime::modify

(PHP 5 >= 5.2.0)

DateTime::modifyAlters the timestamp

Description

Object oriented style

public DateTime DateTime::modify ( string $modify )

Procedural style

DateTime date_modify ( DateTime $object , string $modify )

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

Parameters

object

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

modify

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.

Changelog

Version Description
5.3.0Changed the return value on success from NULL to DateTime.

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


DateTime
PHP Manual