有时有用的创建日期由一个操作符，如在BIRT参数

我在1个月前用:

new Date(new Date().setMonth(new Date().getMonth()-1));   

我已经通过使用Moment Js库完成了 参考文献:https://momentjs.com/

   startDate = new Date()
   endDate = moment(startDate).add(2, "Months").format("YYYY-MM-DD")
   endDate= new Date (endDate)

下面是一个如何根据日期输入(membershipssignup_date) +通过表单字段添加的月份(membershipsmonths)计算未来日期的示例。

membershipsmonths字段的默认值为0

触发链接(可以是附加到成员资格术语字段的onchange事件):

<a href="#" onclick="calculateMshipExp()"; return false;">Calculate Expiry Date</a>

function calculateMshipExp() {

var calcval = null;

var start_date = document.getElementById("membershipssignup_date").value;
var term = document.getElementById("membershipsmonths").value;  // Is text value

var set_start = start_date.split('/');  

var day = set_start[0];  
var month = (set_start[1] - 1);  // January is 0 so August (8th month) is 7
var year = set_start[2];
var datetime = new Date(year, month, day);
var newmonth = (month + parseInt(term));  // Must convert term to integer
var newdate = datetime.setMonth(newmonth);

newdate = new Date(newdate);
//alert(newdate);

day = newdate.getDate();
month = newdate.getMonth() + 1;
year = newdate.getFullYear();

// This is British date format. See below for US.
calcval = (((day <= 9) ? "0" + day : day) + "/" + ((month <= 9) ? "0" + month : month) + "/" + year);

// mm/dd/yyyy
calcval = (((month <= 9) ? "0" + month : month) + "/" + ((day <= 9) ? "0" + day : day) + "/" + year);

// Displays the new date in a <span id="memexp">[Date]</span> // Note: Must contain a value to replace eg. [Date]
document.getElementById("memexp").firstChild.data = calcval;

// Stores the new date in a <input type="hidden" id="membershipsexpiry_date" value="" name="membershipsexpiry_date"> for submission to database table
document.getElementById("membershipsexpiry_date").value = calcval;
}

var a=new Date();
a.setDate(a.getDate()+5);

如上所述的方法，您可以添加月到日期功能。

这个函数处理边缘情况，并且速度很快:

function addMonthsUTC (date, count) {
  if (date && count) {
    var m, d = (date = new Date(+date)).getUTCDate()

    date.setUTCMonth(date.getUTCMonth() + count, 1)
    m = date.getUTCMonth()
    date.setUTCDate(d)
    if (date.getUTCMonth() !== m) date.setUTCDate(0)
  }
  return date
}

测试:

> d = new Date('2016-01-31T00:00:00Z');
Sat Jan 30 2016 18:00:00 GMT-0600 (CST)
> d = addMonthsUTC(d, 1);
Sun Feb 28 2016 18:00:00 GMT-0600 (CST)
> d = addMonthsUTC(d, 1);
Mon Mar 28 2016 18:00:00 GMT-0600 (CST)
> d.toISOString()
"2016-03-29T00:00:00.000Z"

非utc日期更新:(由A.Hatchkins编写)

function addMonths (date, count) {
  if (date && count) {
    var m, d = (date = new Date(+date)).getDate()

    date.setMonth(date.getMonth() + count, 1)
    m = date.getMonth()
    date.setDate(d)
    if (date.getMonth() !== m) date.setDate(0)
  }
  return date
}

测试:

> d = new Date(2016,0,31);
Sun Jan 31 2016 00:00:00 GMT-0600 (CST)
> d = addMonths(d, 1);
Mon Feb 29 2016 00:00:00 GMT-0600 (CST)
> d = addMonths(d, 1);
Tue Mar 29 2016 00:00:00 GMT-0600 (CST)
> d.toISOString()
"2016-03-29T06:00:00.000Z"

正如大多数答案突出显示的那样，我们可以使用setMonth()方法和getMonth()方法一起为给定的日期添加特定的月份数。

例子:(@ChadD在他的回答中提到。)

Var x = 12;//或任何偏移量 var CurrentDate = new Date(); CurrentDate.setMonth(CurrentDate.getMonth() + x);

但是我们应该小心地使用这个解决方案，因为我们会在边界情况下遇到麻烦。

要处理边缘情况，下面链接中给出的答案是有帮助的。 https://stackoverflow.com/a/13633692/3668866