1. 
   /**
2. * 判斷某年的某月有多少天
3. * @return [type] [description]
4. */
5. function daysInmonth($year=‘‘,$month=‘‘){
6. if(empty($year)) $year = date(‘Y‘);
7. if(empty($month)) $month = date(‘m‘);
8. if (in_array($month, array(1, 3, 5, 7, 8, ‘01‘, ‘03‘, ‘05‘, ‘07‘, ‘08‘, 10, 12))) {
9. $text = ‘31‘; //
   月大
10. }elseif ($month == 2 || $month == ‘02‘){
11. if ( ($year % 400 == 0) || ( ($year % 4 == 0) && ($year % 100 !== 0) ) ) { //判斷是否是閏年
12. $text = ‘29‘; //閏年2月
13. } else {
14. $text = ‘28‘; //平年2月
15. }
16. } else {
17. $text = ‘30‘; //月小
18. }
20. return $text;

21.}

/**

1. * 判斷某年的某月有多少天
2. * @return
   [type] [description]
3. */
4. function daysInmonth1($year=‘‘,$month=‘‘){
5. if(empty($year)) $year = date(‘Y‘);
6. if(empty($month)) $month = date(‘m‘);
7. $day = ‘01‘;
9. //檢測日期是否合法
10. if(!checkdate($month,$day,$year)) return ‘輸入的時間有誤‘;
12. //獲取當年當月第一天的時間戳(時,分,秒,月,日,年)
13. $timestamp = mktime(0,0,0,$month,$day,$year);
14. $result = date(‘t‘,$timestamp);
15. return $result;

16.}

php判斷該月有多少天