how to find the expired date in php

hi i need to find whether the given date is passed or future.

$elapsedTime = new DateTime('2011-03-15 00:20:00');
$elapsedInt = $elapsedTime->diff( new DateTime() );
echo ( $elapsedInt->inv开发者_运维问答ert ? 'Future' : 'Past' ) . "<br/>";

i tried this code but i am getting error because my php version was 5,2.And i cant update.

can any one help me ?

You can do a simple comparison:

$now = new DateTime();

echo ($now < $elapsedTime ? 'Future' : 'Past');

$elapsedTime = new DateTime('2011-03-15 00:20:00');
$now         = new DateTime();
echo ($now < $elapsedTime ? 'Future' : 'Past');