Проверка формата даты в PHP

<?php function checkDateFormat($date) { //match the format of the date if (preg_match ("/^([0-9]{4})-([0-9]{2})-([0-9]{2})$/", $date, $parts)) { //check weather the date is valid of not if(checkdate($parts[2],$parts[3],$parts[1])) return true; else return false; } else return false; } ?>