<!DOCTYPE html>
<html>
<body>
<?php
$date=date_create("2013-05-01");
date_time_set($date,13,24);
echo date_format($date,"Y-m-d H:i:s") . "<br>";
date_time_set($date,12,20,55);
echo date_format($date,"Y-m-d H:i:s");
?>
</body>
</html>