normally you could use the strtotime() function but it expects the date elements in a different order. So you can use the mktime() function:
<?
$date1 = '13/05/02';
$date2 = '03/06/02';
$date1_array = explode ('/', $date1);
$date2_array = explode ('/', $date2);
$date1_timestamp = mktime (0,0,0,$date1_array[1],$date1_array[0],$date1_array[2]);
$date2_timestamp = mktime (0,0,0,$date2_array[1],$date2_array[0],$date2_array[2]);
if ($date1_timestamp < $date2_timestamp)
{
echo "$date1 is earlier than $date2";
}
else
{
echo "$date1 is later than $date2";
}
?>