(PHP 5 >= 5.3.0)
DateTime::sub — Subtracts an amount of days, months, years, hours, minutes and seconds from a DateTime object
Subtracts the specified DateInterval object from the specified DateTime object.
Procedural style only: A DateTime object returned by date_create()
A DateInterval object
Returns the modified DateTime.
Example #1 date_sub() example
<?php
$date = new DateTime("18-July-2008 16:30:30");
echo $date->format("d-m-Y H:i:s").'<br />';
date_sub($date, new DateInterval("P5D"));
echo '<br />'.$date->format("d-m-Y").' : 5 Days';
date_sub($date, new DateInterval("P5M"));
echo '<br />'.$date->format("d-m-Y").' : 5 Months';
date_sub($date, new DateInterval("P5Y"));
echo '<br />'.$date->format("d-m-Y").' : 5 Years';
date_sub($date, new DateInterval("P5Y5M5D"));
echo '<br />'.$date->format("d-m-Y").' : 5 Days, 5 Months, 5 Years';
date_sub($date, new DateInterval("P5YT5H"));
echo '<br />'.$date->format("d-m-Y H:i:s").' : 5 Years, 5 Hours';
?>