Question

I have this function which formats seconds to 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);
    return minutes + ":" + seconds; 
}

it works great but i need a function to turn milliseconds to time and I cant seem to understand what i need to do to this function to return time in this format

mm:ss.mill
01:28.5568

Answer 1

Lots of unnecessary flooring in other answers. If the string is in milliseconds, convert to h:m:s as follows:

function msToTime(s) {
  var ms = s % 1000;
  s = (s - ms) / 1000;
  var secs = s % 60;
  s = (s - secs) / 60;
  var mins = s % 60;
  var hrs = (s - mins) / 60;

  return hrs + ':' + mins + ':' + secs + '.' + ms;
}

If you want it formatted as hh:mm:ss.sss then use:

function msToTime(s) {

  // Pad to 2 or 3 digits, default is 2
  function pad(n, z) {
    z = z || 2;
    return ('00' + n).slice(-z);
  }

  var ms = s % 1000;
  s = (s - ms) / 1000;
  var secs = s % 60;
  s = (s - secs) / 60;
  var mins = s % 60;
  var hrs = (s - mins) / 60;

  return pad(hrs) + ':' + pad(mins) + ':' + pad(secs) + '.' + pad(ms, 3);
}

console.log(msToTime(55018))

Using some recently added language features, the pad function can be more concise:

function msToTime(s) {
    // Pad to 2 or 3 digits, default is 2
  var pad = (n, z = 2) => ('00' + n).slice(-z);
  return pad(s/3.6e6|0) + ':' + pad((s%3.6e6)/6e4 | 0) + ':' + pad((s%6e4)/1000|0) + '.' + pad(s%1000, 3);
}

// Current hh:mm:ss.sss UTC
console.log(msToTime(new Date() % 8.64e7))