public static function daysInMonth($month, $year) { if (in_array($month, array(1, 3, 5, 7, 8, 10, 12))) { return 31; } if (in_array($month, array(4, 6, 9, 11))) { return 30; } if ($month == 2) { if (DayTime::isLeapYear($year)) { return 29; } else { return 28; } } }