Check if a string is a valid date

isValidDate.php

function isValidDate($date, $format = "d-m-Y H:i:s")
{
    //since php 5.3
    $parsedate = date_parse_from_format($format, $date);
    $datetmp = mktime($parsedate['hour'], $parsedate['minute'], $parsedate['second'], $parsedate['month'], $parsedate['day'], $parsedate['year']);

    return (strtotime($date) == $datetmp) ? true : false;
}