PHP | cal_days_in_month()
cal_days_in_month() 是一个内置函数，它返回指定日历的特定月份的天数。我们必须传递日历类型、月份和年份作为参数，该函数将返回指定日历年的该月的天数。
句法
int cal_days_in_month ( int $calendar, int $month, int $year )参数 ：
- Calendar :用于计算的日历类型。该值是必需的。
- 月：所选日历中的月份。该值是必需的。
- Year ：所选日历中的年份。该值也是必需的。
以下是“日历”参数可以包含的可能值列表：
- CAL_GREGORIAN
- CAL_JULIAN
- CAL_JEWISH
- CAL_FRENCH
- CAL_NUM_CALS
- CAL_DOW_DAYNO
- CAL_DOW_SHORT
- CAL_DOW_LONG
- CAL_MONTH_GREGORIAN_SHORT
- CAL_MONTH_GREGORIAN_LONG
- CAL_MONTH_JULIAN_SHORT
- CAL_MONTH_JULIAN_LONG
- CAL_MONTH_JEWISH
- CAL_MONTH_FRENCH
- CAL_EASTER_DEFAULT
- CAL_EASTER_ROMAN
- CAL_EASTER_ALWAYS_GREGORIAN
- CAL_EASTER_ALWAYS_JULIAN
- CAL_JEWISH_ADD_ALAFIM_GERESH
- CAL_JEWISH_ADD_ALAFIM
- CAL_JEWISH_ADD_GERESHAYIM
返回值：返回指定日历在一年中的月份中的天数。
php
";
$d = cal_days_in_month(CAL_GREGORIAN, 2, 2004); // Calendar Type - Gregorian
echo "There was $d days in February 2004.";
?>
输出 ：
There was 28 days in February 1965.
There was 29 days in February 2004.