get total day of month
// 3 method
// one:
function get_total_day_of_month($month, $year) {
$day = 0;
switch ($month) {
case 1:
case 3:
case 5:
case 7:
case 8:
case 10:
case 12:
$day = 31;
break;
case 4:
case 6:
case 9:
case 11:
$day = 30;
break;
case 2:
if ($year % 100 != 0 && $year % 4 == 0) {
$day = 29;
} else {
$day = 28;
}
break;
default: $day = 0;
}
return $day;
}
// two:
function days_in_month($month, $year) {
// calculate number of days in a month
return $month == 2 ? ($year % 4 ? 28 : ($year % 100 ? 29 : ($year % 400 ? 28 : 29))) : (($month - 1) % 7 % 2 ? 30 : 31);
}
// three: use cal_days_in_month (PHP 5.6, 7, 8)
$total_start_day_month = cal_days_in_month(CAL_GREGORIAN, 2, 2020);
echo ( $total_start_day_month );
echo ( "<br>");
// how to apply
$total_start_day_month = get_total_day_of_month(2, 2020);
echo ( $total_start_day_month );
echo ( "<br>");
$total_start_day_month = days_in_month(2, 2020);
echo ( $total_start_day_month );
echo ( "<br>");
echo (date('t', strtotime('2020-02-1')));