JAVASCRIPT

convert date to millisecond in javascript

var date = new Date("11/21/1987 16:00:00"); // some mock date
var milliseconds = date.getTime(); 
// This will return you the number of milliseconds
// elapsed from January 1, 1970 
// if your date is less than that date, the value will be negative

console.log(milliseconds);

how to convert milliseconds to time in javascript

const milliseconds = 1575909015000

const dateObject = new Date(milliseconds)

const humanDateFormat = dateObject.toLocaleString() //2019-12-9 10:30:15

dateObject.toLocaleString("en-US", {weekday: "long"}) // Monday
dateObject.toLocaleString("en-US", {month: "long"}) // December
dateObject.toLocaleString("en-US", {day: "numeric"}) // 9
dateObject.toLocaleString("en-US", {year: "numeric"}) // 2019
dateObject.toLocaleString("en-US", {hour: "numeric"}) // 10 AM
dateObject.toLocaleString("en-US", {minute: "numeric"}) // 30
dateObject.toLocaleString("en-US", {second: "numeric"}) // 15
dateObject.toLocaleString("en-US", {timeZoneName: "short"}) // 12/9/2019, 10:30:15 AM CST

milliseconds to date javascript

	//Date.now() gives us the current time in milliseconds counted from 1970-01-01
const todaysDate = Date.now();
    //Let's add 1 year of milliseconds. 
    // We know that there is 1000 milliseconds in 1 second. 
    // 60 seconds in 1 minute, 
    // 60 minutes in 1 hour, 
    // 24 hours in 1 day 
    // and 365 days in one year (leap year not included)
const dateInOneYear = new Date(todaysDate+(1000*60*60*24*365)); 
    //To print them out in a readable way
console.log(new Date(todaysDate).toLocaleDateString())
console.log(new Date(dateInOneYear).toLocaleDateString())

convert milliseconds to time javascript

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))

javascript new Date(milliseconds)

const time1 = new Date(0);

// epoch time
console.log(time1); // Thu Jan 01 1970 05:30:00

// 100000000000 milliseconds after the epoch time
const time2 = new Date(100000000000)
console.log(time2); // Sat Mar 03 1973 15:16:40

get date in milliseconds javascript

var myDate = +new Date("2012-02-10T13:19:11+0000");

milliseconds to date javascript

var d = new Date(1469433907836); // Parameter should be long value

d.toLocaleString()     // 7/25/2016, 1:35:07 PM
d.toLocaleDateString() // 7/25/2016
d.toDateString()       // Mon Jul 25 2016
d.toTimeString()       // 13:35:07 GMT+0530 (India Standard Time)
d.toLocaleTimeString() // 1:35:07 PM
d.toISOString();       // 2016-07-25T08:05:07.836Z
d.toJSON();            // 2016-07-25T08:05:07.836Z
d.toString();          // Mon Jul 25 2016 13:35:07 GMT+0530 (India Standard Time)
d.toUTCString();       // Mon, 25 Jul 2016 08:05:07 GMT

milliseconds to time in 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)