(PHP 4 >= 4.1.0, PHP 5)
cal_days_in_month — Return the number of days in a month for a given year and calendar
This function will return the number of days in the month of year for the specified calendar.
Calendar to use for calculation
Month in the selected calendar
Year in the selected calendar
The length in days of the selected month in the given calendar
Example #1 cal_days_in_month() example
<?php
$num = cal_days_in_month(CAL_GREGORIAN, 8, 2003); // 31
echo "There was $num days in August 2003";
?>