以下是2019年更新的一句话:

//your date
var someDate = new Date("Wed Jun 26 2019 09:38:02 GMT+0100") 

var result = `${String(someDate.getHours()).padStart(2,"0")}:${String(someDate.getMinutes()).padStart(2,"0")}:${String(someDate.getSeconds()).padStart(2,"0")}`

//result will be "09:38:02"

这很简单，

function toTimeString(seconds) {
  return (new Date(seconds * 1000)).toUTCString().match(/(\d\d:\d\d:\d\d)/)[0];
}

最普遍的答案是

function hms(seconds) {
  return [3600, 60]
    .reduceRight(
      (p, b) => r => [Math.floor(r / b)].concat(p(r % b)),
      r => [r]
    )(seconds)
    .map(a => a.toString().padStart(2, '0'))
    .join(':');
}

一些示例输出:

> hms(0)
< "00:00:00"

> hms(5)
< "00:00:05"

> hms(60)
< "00:01:00"

> hms(3785)
< "01:03:05"

> hms(37850)
< "10:30:50"

> hms(378500)
< "105:08:20"

详见https://stackoverflow.com/a/66504936/1310733

主题的变奏。处理个位数秒的方式有点不同

seconds2time(0)  ->  "0s" 
seconds2time(59) -> "59s" 
seconds2time(60) -> "1:00" 
seconds2time(1000) -> "16:40" 
seconds2time(4000) -> "1:06:40"

function seconds2time (seconds) {
    var hours   = Math.floor(seconds / 3600);
    var minutes = Math.floor((seconds - (hours * 3600)) / 60);
    var seconds = seconds - (hours * 3600) - (minutes * 60);
    var time = "";

    if (hours != 0) {
      time = hours+":";
    }
    if (minutes != 0 || time !== "") {
      minutes = (minutes < 10 && time !== "") ? "0"+minutes : String(minutes);
      time += minutes+":";
    }
    if (time === "") {
      time = seconds+"s";
    }
    else {
      time += (seconds < 10) ? "0"+seconds : String(seconds);
    }
    return time;
}

function secondsToTime(secs)
{
    var hours = Math.floor(secs / (60 * 60));

    var divisor_for_minutes = secs % (60 * 60);
    var minutes = Math.floor(divisor_for_minutes / 60);

    var divisor_for_seconds = divisor_for_minutes % 60;
    var seconds = Math.ceil(divisor_for_seconds);

    if(hours >= 12)
    {
     var m= 'pm' ;
     }
     else
     {
         var m='am'
     }
     if(hours-12 >0)
     {
            var hrs = hours-12;
     }
     else if(hours-12 <0)
     {
            var hrs = hours;
     }
    var obj = {
        "h": hrs,
        "m": minutes,
        "s": seconds,
        "a":m
    };


    return obj;
}
var d = new Date();
var n = d.getHours();
var hms = d.getHours()+':'+d.getMinutes()+':'+d.getSeconds();   // your input string
var a = hms.split(':'); // split it at the colons

// minutes are worth 60 seconds. Hours are worth 60 minutes.
var seconds = (+a[0]) * 60 * 60 + (+a[1]) * 60 + (+a[2]); 




console.log(seconds);
console.log(secondsToTime(seconds))

https://jsfiddle.net/jithinksoft/9x6z4sdt/

你可以在没有任何外部JS库的帮助下使用JS Date方法做到这一点，如下所示:

var date = new date (0); date.setSeconds (45);//指定SECONDS的值 var timeString = date.toISOString()。substring(11、19); console.log (timeString)