bool checkdate ( int $month , int $day , int $year )

<?php

$date = "01-01-1980 <script>alert('test');</script>";
$aDate_parts = preg_split("/[\s-]+/", $date);

var_dump(
    checkdate(
        $aDate_parts[1], // Month
        $aDate_parts[0], // Day
        $aDate_parts[2] // Year
    )
);

?>