function ctime($t) { 
    $s = new DateTime('@0'); 
    $s->add(new DateInterval($t)); 
	if (strlen($t)>8) 
		return $s->format('g:i:s'); 
	    else 
		return $s->format('i:s'); 
} 

echo ctime('PT3M44S'); // return: 03:44