Check num day of month

PHP function

function getMonthDayNum($month, $year) {
 $month = (int)$month;
 $year = (int)$year;
 $days = 30;
 switch ($month) {
  case 1: case 3: case 5: case 7: case 8: case 10: case 12:
   $days = 31;
   break;
  case 2:
   if (($year % 100 === 0 && $year % 400 === 0) || $year % 4 === 0) {
    $days = 29;
   } else {
    $days = 28;
   }
   break;
 }
 return $days;
}

Javascript function

function getMonthDayNum(month, year) {
 month = Number(month);
 year = Number(year);
 days = 30;
 switch (month) {
  case 1: case 3: case 5: case 7: case 8: case 10: case 12:
   days = 31;
   break;
  case 2:
   if ((year % 100 === 0 && year % 400 === 0) || year % 4 === 0) {
    days = 29;
   } else {
    days = 28;
   }
   break;
 }
 return days;
}