cal_days_in_month

(PHP 4 >= 4.1.0, PHP 5, PHP 7, PHP 8)

cal_days_in_month — Return the number of days in a month for a given year and calendar

cal_days_in_month(int $calendar, int $month, int $year): int

This function will return the number of days in the month of year for the specified calendar.

The length in days of the selected month in the given calendar

Example #1 cal_days_in_month() example

<?php
$number = cal_days_in_month(CAL_GREGORIAN, 8, 2003); // 31
echo "There were {$number} days in August 2003";
?>