- substr: documentation ( source)
- rawurldecode: documentation ( source)
<?php
$DateString = rawurldecode('Tue%20Oct%2015%202013%2001:00:00%20GMT+0100%20(BST)');
echo substr(rawurldecode($DateString), 3);
//echo date('Y-m-d H:i:s', strtotime($DateString));
?>