您尝试过向Date对象添加秒数吗?

Date.prototype.addSeconds = function(seconds) {
    this.setSeconds(this.getSeconds() + seconds);
};
var dt = new Date();
dt.addSeconds(1234);

一个示例: https://jsfiddle.net/j5g2p0dc/5/

更新: 样本链接缺失，所以我创建了一个新的。

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.
    }
}

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;
}

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');

在JavaScript Date方法的帮助下，你可以在没有任何外部JavaScript库的情况下做到这一点，如下:

const date = new Date(null);
date.setSeconds(SECONDS); // specify value for SECONDS here
const result = date.toISOString().slice(11, 19);

或者，按照@Frank的评论;一句话:

new Date(SECONDS * 1000).toISOString().slice(11, 19);

这招很管用:

function secondstotime(secs)
{
    var t = new Date(1970,0,1);
    t.setSeconds(secs);
    var s = t.toTimeString().substr(0,8);
    if(secs > 86399)
        s = Math.floor((t - Date.parse("1/1/70")) / 3600000) + s.substr(2);
    return s;
}

(来源此处)