public static function getMonthEnd($month = -1, $year = -1)
    {
        if ($month == -1) {
            $month = date("n");
        }
        if ($year == -1) {
            $year = date("Y");
        }

        //gets the number of days in the actual month
        $tempTime = mktime(0, 0, 0, $month, 1, $year);
        $tempTime = date("t", $tempTime);

        return mktime(23, 59, 59, $month, $tempTime, $year);
    }