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

我从其他答案中得到一些灵感,使输入具有自动卫生。我希望这是对其他答案的改进。

我还推荐使用<input type="date">字段,这将有助于验证用户输入。

//use best practices by labeling your constants. let MS_PER_SEC = 1000 , SEC_PER_HR = 60 * 60 , HR_PER_DAY = 24 , MS_PER_DAY = MS_PER_SEC * SEC_PER_HR * HR_PER_DAY ; //let's assume we get Date objects as arguments, otherwise return 0. function dateDiffInDays(date1Time, date2Time) { if (!date1Time || !date2Time) return 0; return Math.round((date2Time - date1Time) / MS_PER_DAY); } function getUTCTime(dateStr) { const date = new Date(dateStr); // If use 'Date.getTime()' it doesn't compute the right amount of days // if there is a 'day saving time' change between dates return Date.UTC(date.getFullYear(), date.getMonth(), date.getDate()); } function calcInputs() { let date1 = document.getElementById("date1") , date2 = document.getElementById("date2") , resultSpan = document.getElementById("result") ; if (date1.value && date2.value && resultSpan) { //remove non-date characters console.log(getUTCTime(date1.value)); let date1Time = getUTCTime(date1.value) , date2Time = getUTCTime(date2.value) , result = dateDiffInDays(date1Time, date2Time) ; resultSpan.innerHTML = result + " days"; } } window.onload = function() { calcInputs(); }; //some code examples console.log(dateDiffInDays(new Date("1/15/2019"), new Date("1/30/2019"))); console.log(dateDiffInDays(new Date("1/15/2019"), new Date("2/30/2019"))); console.log(dateDiffInDays(new Date("1/15/2000"), new Date("1/15/2019"))); <input type="date" id="date1" value="2000-01-01" onchange="calcInputs();" /> <input type="date" id="date2" value="2022-01-01" onchange="calcInputs();"/> Result: <span id="result"></span>

其他回答

您可以使用UnderscoreJS来格式化和计算差异。

演示https://jsfiddle.net/sumitridhal/8sv94msp/

var startDate = moment(“206 -08- 29t23:35:01”); var endDate = moment(“206 -08- 30t23:35:01”); 游戏机。log (startDate); 游戏机。log (endDate); var结果= endDate。diff(startDate, hours, true); 文件。 文档全身appendChild(文档。createTextNode (resultHours)); 身体(白色空间:pre;font-family: monospace;) “https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.5.1/moment.min.js”< script src = > / < script >

使用Moment.js

Var future = moment('05/02/2015'); Var start = moment('04/23/2015'); Var d =未来。diff(开始,“天”);/ / 9 console.log (d); < script src = " https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.17.1/moment-with-locales.min.js " > < /脚本>

在撰写本文时,其他答案中只有一个正确处理DST(夏令时)转换。以下是位于加州的一个系统的结果:

                                        1/1/2013- 3/10/2013- 11/3/2013-
User       Formula                      2/1/2013  3/11/2013  11/4/2013  Result
---------  ---------------------------  --------  ---------  ---------  ---------
Miles                   (d2 - d1) / N   31        0.9583333  1.0416666  Incorrect
some         Math.floor((d2 - d1) / N)  31        0          1          Incorrect
fuentesjr    Math.round((d2 - d1) / N)  31        1          1          Correct
toloco     Math.ceiling((d2 - d1) / N)  31        1          2          Incorrect

N = 86400000

虽然数学。round返回正确的结果,我认为它有点笨拙。相反,当DST开始或结束时,通过显式计算UTC偏移量的变化,我们可以使用精确的算术:

function treatAsUTC(date) {
    var result = new Date(date);
    result.setMinutes(result.getMinutes() - result.getTimezoneOffset());
    return result;
}

function daysBetween(startDate, endDate) {
    var millisecondsPerDay = 24 * 60 * 60 * 1000;
    return (treatAsUTC(endDate) - treatAsUTC(startDate)) / millisecondsPerDay;
}

alert(daysBetween($('#first').val(), $('#second').val()));

解释

JavaScript的日期计算很棘手,因为date对象内部存储的时间是UTC,而不是本地时间。例如,3/10/2013太平洋标准时间12:00 AM (UTC-08:00)存储为3/10/2013上午8:00 UTC, 3/11/2013太平洋夏令时12:00 AM (UTC-07:00)存储为3/11/2013上午7:00 UTC。在这一天,从午夜到午夜,当地时间在UTC只有23小时!

虽然本地时间中的一天可以大于或小于24小时,但国际标准时间中的一天总是24小时上面所示的daysBetween方法利用了这一事实,它首先调用treatAsUTC将本地时间调整为午夜UTC,然后再进行减法和除法。

1. JavaScript忽略闰秒。

function timeDifference(date1, date2) { var oneDay = 24 * 60 * 60; // hours*minutes*seconds var oneHour = 60 * 60; // minutes*seconds var oneMinute = 60; // 60 seconds var firstDate = date1.getTime(); // convert to milliseconds var secondDate = date2.getTime(); // convert to milliseconds var seconds = Math.round(Math.abs(firstDate - secondDate) / 1000); //calculate the diffrence in seconds // the difference object var difference = { "days": 0, "hours": 0, "minutes": 0, "seconds": 0, } //calculate all the days and substract it from the total while (seconds >= oneDay) { difference.days++; seconds -= oneDay; } //calculate all the remaining hours then substract it from the total while (seconds >= oneHour) { difference.hours++; seconds -= oneHour; } //calculate all the remaining minutes then substract it from the total while (seconds >= oneMinute) { difference.minutes++; seconds -= oneMinute; } //the remaining seconds : difference.seconds = seconds; //return the difference object return difference; } console.log(timeDifference(new Date(2017,0,1,0,0,0),new Date()));

我认为解决方案不是100%正确的,我会使用天花板而不是地板,圆形将工作,但这不是正确的操作。

function dateDiff(str1, str2){
    var diff = Date.parse(str2) - Date.parse(str1); 
    return isNaN(diff) ? NaN : {
        diff: diff,
        ms: Math.ceil(diff % 1000),
        s: Math.ceil(diff / 1000 % 60),
        m: Math.ceil(diff / 60000 % 60),
        h: Math.ceil(diff / 3600000 % 24),
        d: Math.ceil(diff / 86400000)
    };
}