我只是想对上面这个不错的答案做一点解释:

var totalSec = new Date().getTime() / 1000;
var hours = parseInt( totalSec / 3600 ) % 24;
var minutes = parseInt( totalSec / 60 ) % 60;
var seconds = totalSec % 60;

var result = (hours < 10 ? "0" + hours : hours) + "-" + (minutes < 10 ? "0" + minutes : minutes) + "-" + (seconds  < 10 ? "0" + seconds : seconds);

On the second line, since there are 3600 seconds in 1 hour, we divide the total number of seconds by 3600 to get the total number of hours. We use parseInt to strip off any decimal. If totalSec was 12600 (3 and half hours), then parseInt( totalSec / 3600 ) would return 3, since we will have 3 full hours. Why do we need the % 24 in this case? If we exceed 24 hours, let's say we have 25 hours (90000 seconds), then the modulo here will take us back to 1 again, rather than returning 25. It is confining the result within a 24 hour limit, since there are 24 hours in one day.

当你看到这样的东西:

25 % 24

你可以这样想:

25 mod 24 or what is the remainder when we divide 25 by 24

var  timeInSec = "661"; //even it can be string

String.prototype.toHHMMSS = function () { 
   /* extend the String by using prototypical inheritance */
    var seconds = parseInt(this, 10); // don't forget the second param
    var hours   = Math.floor(seconds / 3600);
    var minutes = Math.floor((seconds - (hours * 3600)) / 60);
    seconds = seconds - (hours * 3600) - (minutes * 60);

    if (hours   < 10) {hours   = "0"+hours;}
    if (minutes < 10) {minutes = "0"+minutes;}
    if (seconds < 10) {seconds = "0"+seconds;}
    var time    = hours+':'+minutes+':'+seconds;
    return time;
}

alert("5678".toHHMMSS());   // "01:34:38"
console.log(timeInSec.toHHMMSS());   //"00:11:01"

我们可以把这个函数写得更短更清晰，但这会降低可读性，所以我们要把它写得尽可能简单，尽可能稳定。

或者你可以在这里检查一下:

在一行中，使用T.J.克劳德的解决方案:

secToHHMMSS = seconds => `${Math.floor(seconds / 3600)}:${Math.floor((seconds % 3600) / 60)}:${Math.floor((seconds % 3600) % 60)}`

在一行中，另一个计算天数的解决方案:

secToDHHMMSS = seconds => `${parseInt(seconds / 86400)}d ${new Date(seconds * 1000).toISOString().substr(11, 8)}`

来源:https://gist.github.com/martinbean/2bf88c446be8048814cf02b2641ba276

一个好的选择是使用Intl.DateTimeFormat。例子:

const timeFormat = new Intl.DateTimeFormat('es-US', {
    hour: 'numeric',
    minute: 'numeric',
    second: 'numeric',
    hour12: false,
    timeZone: 'UTC'
});

const endTimeFormatted = timeFormat.format(new Date(SECS * 1000); //hour in secs

更新(2020):

请使用@Frank的一句话解决方案:

new Date(SECONDS * 1000).toISOString().substring(11, 16)

如果SECONDS<3600并且你只想显示MM:SS，那么使用下面的代码:

new Date(SECONDS * 1000).toISOString().substring(14, 19)

这是目前为止最好的解决办法。

旧的回答:

使用Moment.js库。

我只是想对上面这个不错的答案做一点解释:

var totalSec = new Date().getTime() / 1000;
var hours = parseInt( totalSec / 3600 ) % 24;
var minutes = parseInt( totalSec / 60 ) % 60;
var seconds = totalSec % 60;

var result = (hours < 10 ? "0" + hours : hours) + "-" + (minutes < 10 ? "0" + minutes : minutes) + "-" + (seconds  < 10 ? "0" + seconds : seconds);

On the second line, since there are 3600 seconds in 1 hour, we divide the total number of seconds by 3600 to get the total number of hours. We use parseInt to strip off any decimal. If totalSec was 12600 (3 and half hours), then parseInt( totalSec / 3600 ) would return 3, since we will have 3 full hours. Why do we need the % 24 in this case? If we exceed 24 hours, let's say we have 25 hours (90000 seconds), then the modulo here will take us back to 1 again, rather than returning 25. It is confining the result within a 24 hour limit, since there are 24 hours in one day.

当你看到这样的东西:

25 % 24

你可以这样想:

25 mod 24 or what is the remainder when we divide 25 by 24