例如，在输入框中给定两个日期:
<input id="first" value="1/1/2000"/>
<input id="second" value="1/1/2001"/>
<script>
alert(datediff("day", first, second)); // what goes here?
</script>
如何在JavaScript中获得两个日期之间的天数?
当前回答
我最近也有同样的问题，因为我来自Java世界，所以我立即开始搜索JavaScript的JSR 310实现。JSR 310是Java的日期和时间API (Java 8的标准版本)。我认为这个API设计得很好。
幸运的是，有一个直接的Javascript端口，称为js-joda。
首先，在<head>中包含js-joda:
<script
src="https://cdnjs.cloudflare.com/ajax/libs/js-joda/1.11.0/js-joda.min.js"
integrity="sha512-piLlO+P2f15QHjUv0DEXBd4HvkL03Orhi30Ur5n1E4Gk2LE4BxiBAP/AD+dxhxpW66DiMY2wZqQWHAuS53RFDg=="
crossorigin="anonymous"></script>
然后简单地这样做:
let date1 = JSJoda.LocalDate.of(2020, 12, 1);
let date2 = JSJoda.LocalDate.of(2021, 1, 1);
let daysBetween = JSJoda.ChronoUnit.DAYS.between(date1, date2);
现在daysBetween包含了间隔的天数。注意，结束日期是独占的。
其他回答
我来找这个小工具在里面你会找到这个的函数。这里有一个简短的例子:
<script type="text/javascript" src="date.js"></script>
<script type="text/javascript">
var minutes = 1000*60;
var hours = minutes*60;
var days = hours*24;
var foo_date1 = getDateFromFormat("02/10/2009", "M/d/y");
var foo_date2 = getDateFromFormat("02/12/2009", "M/d/y");
var diff_date = Math.round((foo_date2 - foo_date1)/days);
alert("Diff date is: " + diff_date );
</script>
计算两个日期之间天数的简单方法是去掉它们的时间分量，即将小时、分钟、秒和毫秒设置为0，然后减去它们的时间，用一天的毫秒值来计算。
var firstDate= new Date(firstDate.setHours(0,0,0,0));
var secondDate= new Date(secondDate.setHours(0,0,0,0));
var timeDiff = firstDate.getTime() - secondDate.getTime();
var diffDays =timeDiff / (1000 * 3600 * 24);
Bookmarklet版本的其他答案，提示你两个日期:
javascript:(function() {
var d = new Date(prompt("First Date or leave blank for today?") || Date.now());
prompt("Days Between", Math.round(
Math.abs(
(d.getTime() - new Date(prompt("Date 2")).getTime())
/(24*60*60*1000)
)
));
})();
下面是datediff的快速实现，作为解决问题的概念证明。它依赖于这样一个事实，即您可以通过减去两个日期之间经过的毫秒，这将它们强制转换为原始数字值(自1970年初以来的毫秒)。
/** * Take the difference between the dates and divide by milliseconds per day. * Round to nearest whole number to deal with DST. */ function datediff(first, second) { return Math.round((second - first) / (1000 * 60 * 60 * 24)); } /** * new Date("dateString") is browser-dependent and discouraged, so we'll write * a simple parse function for U.S. date format (which does no error checking) */ function parseDate(str) { var mdy = str.split('/'); return new Date(mdy[2], mdy[0] - 1, mdy[1]); } alert(datediff(parseDate(first.value), parseDate(second.value))); <input id="first" value="1/1/2000"/> <input id="second" value="1/1/2001"/>
You should be aware that the "normal" Date APIs (without "UTC" in the name) operate in the local timezone of the user's browser, so in general you could run into issues if your user is in a timezone that you don't expect, and your code will have to deal with Daylight Saving Time transitions. You should carefully read the documentation for the Date object and its methods, and for anything more complicated, strongly consider using a library that offers more safe and powerful APIs for date manipulation.
数字和日期——MDN JavaScript指南 日期——MDN JavaScript参考
同样，出于说明的目的，为了简洁起见，该代码段对窗口对象使用了命名访问，但在生产中应该使用getElementById之类的标准化api，或者更有可能使用一些UI框架。
我在Angular中也遇到了同样的问题。我复制了一份，否则他会覆盖第一次约会。两个日期的时间都必须为00:00:00(显然)
/*
* Deze functie gebruiken we om het aantal dagen te bereken van een booking.
* */
$scope.berekenDagen = function ()
{
$scope.booking.aantalDagen=0;
/*De loper is gelijk aan de startdag van je reservatie.
* De copy is nodig anders overschijft angular de booking.van.
* */
var loper = angular.copy($scope.booking.van);
/*Zolang de reservatie beschikbaar is, doorloop de weekdagen van je start tot einddatum.*/
while (loper < $scope.booking.tot) {
/*Tel een dag op bij je loper.*/
loper.setDate(loper.getDate() + 1);
$scope.booking.aantalDagen++;
}
/*Start datum telt natuurlijk ook mee*/
$scope.booking.aantalDagen++;
$scope.infomsg +=" aantal dagen: "+$scope.booking.aantalDagen;
};
