$s = '06/10/2011 19:00:02';
$date = strtotime($s);
echo date('d/M/Y H:i:s', $date);
<?php
$date = DateTime::createFromFormat('j-M-Y', '15-Feb-2009');
echo $date->format('Y-m-d');
?>
<?php
$date = DateTime::createFromFormat('j-M-Y', '15-Feb-2009');
echo $date->format('Y-m-d');
?>