正如Cleiton在他的回答中指出的，moment.js可以用于:

moment().startOf('day')
        .seconds(15457)
        .format('H:mm:ss');

这个函数应该这样做:

var convertTime = function (input, separator) {
    var pad = function(input) {return input < 10 ? "0" + input : input;};
    return [
        pad(Math.floor(input / 3600)),
        pad(Math.floor(input % 3600 / 60)),
        pad(Math.floor(input % 60)),
    ].join(typeof separator !== 'undefined' ?  separator : ':' );
}

在不传递分隔符的情况下，它使用:作为(默认)分隔符:

time = convertTime(13551.9941351); // --> OUTPUT = 03:45:51

如果你想使用-作为分隔符，只需将其作为第二个参数传递:

time = convertTime(1126.5135155, '-'); // --> OUTPUT = 00-18-46

看看这小提琴。

我遇到了一些人提到的情况，其中秒的数量超过了一天。以下是@Harish Anchu评分最高的答案的改编版本，该答案解释了更长的时间:

function secondsToTime(seconds) {
  const arr = new Date(seconds * 1000).toISOString().substr(11, 8).split(':');

  const days = Math.floor(seconds / 86400);
  arr[0] = parseInt(arr[0], 10) + days * 24;

  return arr.join(':');
}

例子:

secondsToTime(101596) // outputs '28:13:16' as opposed to '04:13:16'

当我想象一个时钟或计时器时，我会这样做:

const secondsTo_HHMMSS = (seconds) => {
      //format to a readable friendly timer
      let hour = Math.floor(seconds / 3600);
      let minute = Math.floor((seconds % 3600) / 60);
      let second = seconds % 60;

      if(hour.toString().length === 1) {
            hour = `0${hour}`;
      }
      if(minute.toString().length === 1) {
            minute = `0${minute}`;
      }
      if(second.toString().length === 1) {
            second = `0${second}`;
      };

      let timer = `${hour}-${minute}-${second}`;

      return timer;
}

这里没有一个答案满足我的要求，因为我想能够处理

大量的秒(天)，以及 负数

尽管OP不要求这些，但是覆盖边缘情况是一个很好的实践，特别是当它不需要花费太多精力时。

很明显，当他说秒的时候，OP的意思是秒的数量。为什么要把函数固定在字符串上?

function secondsToTimeSpan(seconds) {
    const value = Math.abs(seconds);
    const days = Math.floor(value / 1440);
    const hours = Math.floor((value - (days * 1440)) / 3600);
    const min = Math.floor((value - (days * 1440) - (hours * 3600)) / 60);
    const sec = value - (days * 1440) - (hours * 3600) - (min * 60);
    return `${seconds < 0 ? '-':''}${days > 0 ? days + '.':''}${hours < 10 ? '0' + hours:hours}:${min < 10 ? '0' + min:min}:${sec < 10 ? '0' + sec:sec}`
}
secondsToTimeSpan(0);       // => 00:00:00
secondsToTimeSpan(1);       // => 00:00:01
secondsToTimeSpan(1440);    // => 1.00:00:00
secondsToTimeSpan(-1440);   // => -1.00:00:00
secondsToTimeSpan(-1);      // => -00:00:01

var time1 = date1.getTime();
var time2 = date2.getTime();
var totalMilisec = time2 - time1;

alert(DateFormat('hh:mm:ss',new Date(totalMilisec)))

 /* ----------------------------------------------------------
 *  Field        | Full Form          | Short Form
 *  -------------|--------------------|-----------------------
 *  Year         | yyyy (4 digits)    | yy (2 digits)
 *  Month        | MMM (abbr.)        | MM (2 digits)
                 | NNN (name)         |
 *  Day of Month | dd (2 digits)      | 
 *  Day of Week  | EE (name)          | E (abbr)
 *  Hour (1-12)  | hh (2 digits)      | 
 *  Minute       | mm (2 digits)      | 
 *  Second       | ss (2 digits)      | 
 *  ----------------------------------------------------------
 */
function DateFormat(formatString,date){
    if (typeof date=='undefined'){
    var DateToFormat=new Date();
    }
    else{
        var DateToFormat=date;
    }
    var DAY         = DateToFormat.getDate();
    var DAYidx      = DateToFormat.getDay();
    var MONTH       = DateToFormat.getMonth()+1;
    var MONTHidx    = DateToFormat.getMonth();
    var YEAR        = DateToFormat.getYear();
    var FULL_YEAR   = DateToFormat.getFullYear();
    var HOUR        = DateToFormat.getHours();
    var MINUTES     = DateToFormat.getMinutes();
    var SECONDS     = DateToFormat.getSeconds();

    var arrMonths = new Array("January","February","March","April","May","June","July","August","September","October","November","December");
    var arrDay=new Array('Sunday','Monday','Tuesday','Wednesday','Thursday','Friday','Saturday');
    var strMONTH;
    var strDAY;
    var strHOUR;
    var strMINUTES;
    var strSECONDS;
    var Separator;

    if(parseInt(MONTH)< 10 && MONTH.toString().length < 2)
        strMONTH = "0" + MONTH;
    else
        strMONTH=MONTH;
    if(parseInt(DAY)< 10 && DAY.toString().length < 2)
        strDAY = "0" + DAY;
    else
        strDAY=DAY;
    if(parseInt(HOUR)< 10 && HOUR.toString().length < 2)
        strHOUR = "0" + HOUR;
    else
        strHOUR=HOUR;
    if(parseInt(MINUTES)< 10 && MINUTES.toString().length < 2)
        strMINUTES = "0" + MINUTES;
    else
        strMINUTES=MINUTES;
    if(parseInt(SECONDS)< 10 && SECONDS.toString().length < 2)
        strSECONDS = "0" + SECONDS;
    else
        strSECONDS=SECONDS;

    switch (formatString){
        case "hh:mm:ss":
            return strHOUR + ':' + strMINUTES + ':' + strSECONDS;
        break;
        //More cases to meet your requirements.
    }
}