下面是另一种更少循环的方法:

calculateTotalMonthsDifference = function(firstDate, secondDate) {
        var fm = firstDate.getMonth();
        var fy = firstDate.getFullYear();
        var sm = secondDate.getMonth();
        var sy = secondDate.getFullYear();
        var months = Math.abs(((fy - sy) * 12) + fm - sm);
        var firstBefore = firstDate > secondDate;
        firstDate.setFullYear(sy);
        firstDate.setMonth(sm);
        firstBefore ? firstDate < secondDate ? months-- : "" : secondDate < firstDate ? months-- : "";
        return months;
}

有两种方法，数学的和快速的，但受制于日历的变幻莫测，或者迭代的和缓慢的，但处理所有奇怪的(或者至少委托处理它们到一个经过良好测试的库)。

If you iterate through the calendar, incrementing the start date by one month & seeing if we pass the end date. This delegates anomaly-handling to the built-in Date() classes, but could be slow IF you're doing this for a large number of dates. James' answer takes this approach. As much as I dislike the idea, I think this is the "safest" approach, and if you're only doing one calculation, the performance difference really is negligible. We tend to try to over-optimize tasks which will only be performed once.

现在，如果您在数据集中计算这个函数，您可能不希望在每一行上运行该函数(或者上帝禁止，每条记录多次)。在这种情况下，您几乎可以使用这里的任何其他答案，除了接受的答案，这是错误的(new Date()和new Date()之间的差异是-1)?

下面是我尝试的一种数学而快速的方法，它解释了不同的月份长度和闰年。你真的应该只使用这样的函数，如果你将应用它到一个数据集(做这个计算一遍又一遍)。如果只需要执行一次，可以使用上面James的迭代方法，因为您正在将所有(许多)异常的处理委托给Date()对象。

function diffInMonths(from, to){
    var months = to.getMonth() - from.getMonth() + (12 * (to.getFullYear() - from.getFullYear()));

    if(to.getDate() < from.getDate()){
        var newFrom = new Date(to.getFullYear(),to.getMonth(),from.getDate());
        if (to < newFrom  && to.getMonth() == newFrom.getMonth() && to.getYear() %4 != 0){
            months--;
        }
    }

    return months;
}

看看我用了什么:

function monthDiff() {
    var startdate = Date.parseExact($("#startingDate").val(), "dd/MM/yyyy");
    var enddate = Date.parseExact($("#endingDate").val(), "dd/MM/yyyy");
    var months = 0;
    while (startdate < enddate) {
        if (startdate.getMonth() === 1 && startdate.getDate() === 28) {
            months++;
            startdate.addMonths(1);
            startdate.addDays(2);
        } else {
            months++;
            startdate.addMonths(1);
        }
    }
    return months;
}

它还计算天数并以月为单位进行转换。

function monthDiff(d1, d2) {
    var months;
    months = (d2.getFullYear() - d1.getFullYear()) * 12;   //calculates months between two years
    months -= d1.getMonth() + 1; 
    months += d2.getMonth();  //calculates number of complete months between two months
    day1 = 30-d1.getDate();  
    day2 = day1 + d2.getDate();
    months += parseInt(day2/30);  //calculates no of complete months lie between two dates
    return months <= 0 ? 0 : months;
}

monthDiff(
    new Date(2017, 8, 8), // Aug 8th, 2017    (d1)
    new Date(2017, 12, 12)  // Dec 12th, 2017   (d2)
);
//return value will be 4 months 

anyVar = (((DisplayTo.getFullYear() * 12) + DisplayTo.getMonth()) - ((DisplayFrom.getFullYear() * 12) + DisplayFrom.getMonth()));

下面的逻辑将在几个月内取得差异

(endDate.getFullYear()*12+endDate.getMonth())-(startDate.getFullYear()*12+startDate.getMonth())