如果在Date中提供0作为dayValue。setFullYear你会得到上个月的最后一天:
d = new Date(); d.setFullYear(2008, 11, 0); // Sun Nov 30 2008
在mozilla中有这种行为的参考。这是一个可靠的跨浏览器功能吗?或者我应该看看其他的方法吗?
当前回答
试试这个:
function _getEndOfMonth(time_stamp) {
let time = new Date(time_stamp * 1000);
let month = time.getMonth() + 1;
let year = time.getFullYear();
let day = time.getDate();
switch (month) {
case 1:
case 3:
case 5:
case 7:
case 8:
case 10:
case 12:
day = 31;
break;
case 4:
case 6:
case 9:
case 11:
day = 30;
break;
case 2:
if (_leapyear(year))
day = 29;
else
day = 28;
break
}
let m = moment(`${year}-${month}-${day}`, 'YYYY-MM-DD')
return m.unix() + constants.DAY - 1;
}
function _leapyear(year) {
return (year % 100 === 0) ? (year % 400 === 0) : (year % 4 === 0);
}
其他回答
对lebreeze提供的解决方案稍加修改:
function daysInMonth(iMonth, iYear)
{
return new Date(iYear, iMonth, 0).getDate();
}
公认的答案不适合我，我是这样做的。
$( function() { $( "#datepicker" ).datepicker(); $('#getLastDateOfMon').on('click', function(){ var date = $('#datepicker').val(); // Format 'mm/dd/yy' eg: 12/31/2018 var parts = date.split("/"); var lastDateOfMonth = new Date(); lastDateOfMonth.setFullYear(parts[2]); lastDateOfMonth.setMonth(parts[0]); lastDateOfMonth.setDate(0); alert(lastDateOfMonth.toLocaleDateString()); }); }); <!doctype html> <html lang="en"> <head> <meta charset="utf-8"> <meta name="viewport" content="width=device-width, initial-scale=1"> <link rel="stylesheet" href="//code.jquery.com/ui/1.12.1/themes/base/jquery-ui.css"> <link rel="stylesheet" href="/resources/demos/style.css"> <script src="https://code.jquery.com/jquery-1.12.4.js"></script> <script src="https://code.jquery.com/ui/1.12.1/jquery-ui.js"></script> </head> <body> <p>Date: <input type="text" id="datepicker"></p> <button id="getLastDateOfMon">Get Last Date of Month </button> </body> </html>
我将使用一个中间日期与下个月的第一天，并返回前一天的日期:
int_d = new Date(2008, 11+1,1);
d = new Date(int_d - 1);
function getLastDay(y, m) {
return 30 + (m <= 7 ? ((m % 2) ? 1 : 0) : (!(m % 2) ? 1 : 0)) - (m == 2) - (m == 2 && y % 4 != 0 || !(y % 100 == 0 && y % 400 == 0));
}
试试这个。
lastDateofTheMonth = new Date(year, month, 0)
例子:
new Date(2012, 8, 0)
输出:
Date {Fri Aug 31 2012 00:00:00 GMT+0900 (Tokyo Standard Time)}
