JavaScript seconds to time string with format hh:mm:ss

I want to convert a duration of time, i.e., number of seconds to colon-separated time string (hh:mm:ss)

I found some useful answers here but they all talk about converting to x hours and x minutes format.

So is there a tiny snippet that does this in jQuery or just raw JavaScript?

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

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

You can use it now like:

alert("5678".toHHMMSS());

Working snippet:

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

    if (hours   < 10) {hours   = "0"+hours;}
    if (minutes < 10) {minutes = "0"+minutes;}
    if (seconds < 10) {seconds = "0"+seconds;}
    return hours + ':' + minutes + ':' + seconds;
}
    
console.log("5678".toHHMMSS());

You can manage to do this without any external JS library with the help of JS Date method like following:

var date = new Date(0);
date.setSeconds(45); // specify value for SECONDS here
var timeString = date.toISOString().substr(11, 8);
console.log(timeString)

To get the time part in the format hh:MM:ss, you can use this regular expression:

(This was mentioned above in same post by someone, thanks for that.)

    var myDate = new Date().toTimeString().replace(/.*(\d{2}:\d{2}:\d{2}).*/, "$1");
    console.log(myDate)

I recommend ordinary javascript, using the Date object. (For a shorter solution, using toTimeString, see the second code snippet.)

var seconds = 9999;
// multiply by 1000 because Date() requires miliseconds
var date = new Date(seconds * 1000);
var hh = date.getUTCHours();
var mm = date.getUTCMinutes();
var ss = date.getSeconds();
// If you were building a timestamp instead of a duration, you would uncomment the following line to get 12-hour (not 24) time
// if (hh > 12) {hh = hh % 12;}
// These lines ensure you have two-digits
if (hh < 10) {hh = "0"+hh;}
if (mm < 10) {mm = "0"+mm;}
if (ss < 10) {ss = "0"+ss;}
// This formats your string to HH:MM:SS
var t = hh+":"+mm+":"+ss;
document.write(t);

(Of course, the Date object created will have an actual date associated with it, but that data is extraneous, so for these purposes, you don't have to worry about it.)

Edit (short solution):

Make use of the toTimeString function and split on the whitespace:

var seconds = 9999; // Some arbitrary value
var date = new Date(seconds * 1000); // multiply by 1000 because Date() requires miliseconds
var timeStr = date.toTimeString().split(' ')[0];

toTimeString gives '16:54:58 GMT-0800 (PST)', and splitting on the first whitespace gives '16:54:58'.