- date_default_timezone_set: documentation ( source)
- date: documentation ( source)
- strtotime: documentation ( source)
<?php
date_default_timezone_set('Europe/Berlin');
$date_now = date('Y-m-d');
$now = strtotime($date_now);
$exp_date = strtotime("2006-02-01");
if ($exp_date<$now){
echo "expired";
}else{
echo "still ok";
}