PHP 某年某月的最后一天

Posted 2023-04-03

求一函数写法.输入参数$y ,$m ,返回整数,表示最后一天的日期数,如果最后一天是29日,返回29,是31日就返回31.

function lastday($y,$m)

……

参考技术A 楼上的那个不对，要改成return date ('d', mktime(0,0,0,$m + 1,0,$y));
才行。本回答被提问者采纳 参考技术B <?php
function lastday($y,$m)

return date ('d', mktime(0,0,0,$m,32,$y));

?>

text 获取某年某月的最后一天和第一天

public static String getFirstAndLastDay(int year, int month) {
    	String firstAndLastDay = "";
		if(year < 0 || month < 1) {
			return "fail";
		}
		Calendar cal = Calendar.getInstance();
		cal.set(Calendar.YEAR, year);
		//Calendar月份从0开始
		cal.set(Calendar.MONTH, month - 1);
		//方便查看
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
		//获取year年month月的开始一天
		int firstDay = cal.getActualMinimum(Calendar.DAY_OF_MONTH);
		//设置Calendar为指定月份的第一天
		cal.set(Calendar.DAY_OF_MONTH, firstDay);
		//指定月份第一天
		firstAndLastDay += sdf.format(cal.getTime())+";";
		
		//指定月份最后一天
		int lastDay = cal.getActualMaximum(Calendar.DAY_OF_MONTH);
		cal.set(Calendar.DAY_OF_MONTH, lastDay);
		firstAndLastDay += sdf.format(cal.getTime());
		
		return firstAndLastDay;
	}