JAVASCRIPT

how to convert seaconds into hh:mm:ss in javascript

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

Convert milliseconds to hh:mm:ss javascript

function padTo2Digits(num) {
  return num.toString().padStart(2, '0');
}

function convertMsToHM(milliseconds) {
  let seconds = Math.floor(milliseconds / 1000);
  let minutes = Math.floor(seconds / 60);
  let hours = Math.floor(minutes / 60);
  seconds = seconds % 60;
  minutes = seconds >= 30 ? minutes + 1 : minutes;
  minutes = minutes % 60;
  hours = hours % 24;
  return `${padTo2Digits(hours)}:${padTo2Digits(minutes)}`;
}

console.log(convertMsToHM(54000000)); //  15:00 (15 hours)
console.log(convertMsToHM(86400000)); //  00:00 (24 hours)
console.log(convertMsToHM(36900000)); //  10:15 (10 hours, 15 minutes)
console.log(convertMsToHM(15335000)); //  04:16 (4 hours, 15 minutes, 35 seconds)
console.log(convertMsToHM(130531000)); // 36:16 (36 hours 15 minutes 31 seconds)