对于HH:MM:SS的特殊情况。MS (eq: "00:04:33.637")， FFMPEG用来指定毫秒。

[-] [HH: MM: SS(打烊……) HH表示小时数，MM表示分钟数 最大值为2位，SS为最大值为2的秒数 位数。最后的m表示SS的十进制值。

/* HH:MM:SS.MS to (FLOAT)seconds ---------------*/ function timerToSec(timer){ let vtimer = timer.split(":") let vhours = +vtimer[0] let vminutes = +vtimer[1] let vseconds = parseFloat(vtimer[2]) return vhours * 3600 + vminutes * 60 + vseconds } /* Seconds to (STRING)HH:MM:SS.MS --------------*/ function secToTimer(sec){ let o = new Date(0) let p = new Date(sec*1000) return new Date(p.getTime()-o.getTime()) .toISOString() .split("T")[1] .split("Z")[0] } /* Example: 7hours, 4 minutes, 33 seconds and 637 milliseconds */ const t = "07:04:33.637" console.log( t + " => " + timerToSec(t) + "s" ) /* Test: 25473 seconds and 637 milliseconds */ const s = 25473.637 // "25473.637" console.log( s + "s => " + secToTimer(s) )

示例使用，毫秒传输计时器:

/* Seconds to (STRING)HH:MM:SS.MS --------------*/ function secToTimer(sec){ let o = new Date(0) let p = new Date(sec*1000) return new Date(p.getTime()-o.getTime()) .toISOString() .split("T")[1] .split("Z")[0] } let job, origin = new Date().getTime() const timer = () => { job = requestAnimationFrame(timer) OUT.textContent = secToTimer((new Date().getTime() - origin) / 1000) } requestAnimationFrame(timer) span {font-size:4rem} <span id="OUT"></span> <br> <button onclick="origin = new Date().getTime()">RESET</button> <button onclick="requestAnimationFrame(timer)">RESTART</button> <button onclick="cancelAnimationFrame(job)">STOP</button>

绑定到媒体元素的示例用法

/* Seconds to (STRING)HH:MM:SS.MS --------------*/ function secToTimer(sec){ let o = new Date(0) let p = new Date(sec*1000) return new Date(p.getTime()-o.getTime()) .toISOString() .split("T")[1] .split("Z")[0] } VIDEO.addEventListener("timeupdate", function(e){ OUT.textContent = secToTimer(e.target.currentTime) }, false) span {font-size:4rem} <span id="OUT"></span><br> <video id="VIDEO" width="400" controls autoplay> <source src="https://www.w3schools.com/html/mov_bbb.mp4" type="video/mp4"> </video>

在问题之外，那些用php编写的函数:

<?php 
/* HH:MM:SS to (FLOAT)seconds ------------------*/
function timerToSec($timer){
  $vtimer = explode(":",$timer);
  $vhours = (int)$vtimer[0];
  $vminutes = (int)$vtimer[1];
  $vseconds = (float)$vtimer[2];
  return $vhours * 3600 + $vminutes * 60 + $vseconds;
}
/* Seconds to (STRING)HH:MM:SS -----------------*/
function secToTimer($sec){
  return explode(" ", date("H:i:s", $sec))[0];  
}

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 sec_to_hms = function(sec){
var min, hours;
     sec = sec - (min = Math.floor(sec/60))*60;
     min = min - (hours = Math.floor(min/60))*60;
     return (hours?hours+':':'') + ((min+'').padStart(2, '0')) + ':'+ ((sec+'').padStart(2, '0'));
}
alert(sec_to_hms(2442542));

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);

我之前用这段代码创建了一个简单的时间跨度对象:

function TimeSpan(time) {
this.hours = 0;
this.minutes = 0;
this.seconds = 0;

while(time >= 3600)
{
    this.hours++;
    time -= 3600;
}

while(time >= 60)
{
    this.minutes++;
    time -= 60;
}

this.seconds = time;
}

var timespan = new Timespan(3662);

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: