$re = '/^(((0[1-9]|1[012])[- \/.]?(0[1-9]|[12][0-9]|3[01])[- \/.]?(19|20)\d\d)|((((0?[13578])|(1[02]))[- \/.]?((0?[1-9])|([12][0-9])|(3[01]))|((0?[469])|(11))[- \/.]?((0?[1-9])|([12][0-9])|(30))|(0?[2])[- \/.]?((0?[1-9])|([1][0-9])|([2][0-8])))[- \/.]?(19\d{2}|20\d{2}))|(((0?[2]))[- \/.]?((0?[1-9])|([12][0-9]))[- \/.]?((19|20)(04|08|[2468][048]|[13579][26])|2000)))$/';
$str = '02022014
222014';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php