(PHP 5 >= 5.1.0)
date_modify — Alters the timestamp
DateTime object.
String in a relative format accepted by strtotime().
Returns NULL on success or FALSE on failure.
Example#1 A date_modify() example
<?php
$date = new DateTime("2006-12-12");
$date->modify("+1 day");
echo $date->format("Y-m-d");
?>
El resultado del ejemplo seria:
2006-12-13