milliseconds to time in javascript

Question

I have this function which formats seconds to time

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


        

Answer 1

Not to reinvent the wheel, here is my favourite one-liner solution:

/**
 * Convert milliseconds to time string (hh:mm:ss:mss).
 *
 * @param Number ms
 *
 * @return String
 */
function time(ms) {
    return new Date(ms).toISOString().slice(11, -1);
}

console.log( time(12345 * 1000) );  // "03:25:45.000"

Method Date.prototype.toISOString() returns a string in simplified extended ISO format (ISO 8601), which is always 24 characters long: YYYY-MM-DDTHH:mm:ss.sssZ. This method is supported in all modern browsers (IE9+) and JavaScript engines.

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UPDATE: The solution above is always limited to range of one day, which is fine if you use it to format milliseconds up to 24 hours (i.e. ms < 86400000). To make it working with any input value, I have extended it into a nice universal prototype method:

/**
 * Convert (milli)seconds to time string (hh:mm:ss[:mss]).
 *
 * @param Boolean isSec
 *
 * @return String
 */
Number.prototype.toTime = function(isSec) {
    var ms = isSec ? this * 1e3 : this,
        lm = ~(4 * !!isSec),  /* limit fraction */
        fmt = new Date(ms).toISOString().slice(11, lm);

    if (ms >= 8.64e7) {  /* >= 24 hours */
        var parts = fmt.split(/:(?=\d{2}:)/);
        parts[0] -= -24 * (ms / 8.64e7 | 0);
        return parts.join(':');
    }

    return fmt;
};

console.log( (12345 * 1000).toTime()     );  // "03:25:45.000"
console.log( (123456 * 789).toTime()     );  // "27:03:26.784"
console.log(  12345.       .toTime(true) );  // "03:25:45"
console.log(  123456789.   .toTime(true) );  // "34293:33:09"