convert time to seconds js code example

Example 1: javascript convert seconds to minutes seconds

function convertHMS(value) {
    const sec = parseInt(value, 10); // convert value to number if it's string
    let hours   = Math.floor(sec / 3600); // get hours
    let minutes = Math.floor((sec - (hours * 3600)) / 60); // get minutes
    let seconds = sec - (hours * 3600) - (minutes * 60); //  get seconds
    // add 0 if value < 10; Example: 2 => 02
    if (hours   < 10) {hours   = "0"+hours;}
    if (minutes < 10) {minutes = "0"+minutes;}
    if (seconds < 10) {seconds = "0"+seconds;}
    return hours+':'+minutes+':'+seconds; // Return is HH : MM : SS
}

Example 2: convert seconds to hours minutes seconds javascript

function secondsToHms(d) {
    d = Number(d);
    var h = Math.floor(d / 3600);
    var m = Math.floor(d % 3600 / 60);
    var s = Math.floor(d % 3600 % 60);

    var hDisplay = h > 0 ? h + (h == 1 ? " hour, " : " hours, ") : "";
    var mDisplay = m > 0 ? m + (m == 1 ? " minute, " : " minutes, ") : "";
    var sDisplay = s > 0 ? s + (s == 1 ? " second" : " seconds") : "";
    return hDisplay + mDisplay + sDisplay; 
}

Example 3: date to seconds js

var date = new Date("2015-08-25T15:35:58.000Z");
var seconds = date.getTime() / 1000; //1440516958