$re = '/^([1-9]|0[1-9]|1[012])([-\/.])([1-9]|0[1-9]|[12][0-9]|3[01])\2(\d{4})$|^(\d{4})([-\/.])([1-9]|0[1-9]|[12][0-9]|3[01])\6([1-9]|0[1-9]|[12][0-9]|3[01])$/';
$str = '14/11/2015';
preg_match($re, $str, $matches, PREG_OFFSET_CAPTURE, 0);
// Print the entire match result
var_dump($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