typescript convert number to time code example

Example 1: javascript int to time format

String.prototype.toHHMMSS = function () {
    var sec_num = parseInt(this, 10); // don't forget the second param
    var hours   = Math.floor(sec_num / 3600);
    var minutes = Math.floor((sec_num - (hours * 3600)) / 60);
    var seconds = sec_num - (hours * 3600) - (minutes * 60);

    if (hours   < 10) {hours   = "0"+hours;}
    if (minutes < 10) {minutes = "0"+minutes;}
    if (seconds < 10) {seconds = "0"+seconds;}
    return hours+':'+minutes+':'+seconds;
}

console.log("5678".toHHMMSS())

Example 2: formating decimal hours as hours and minute javascript

var decimalTimeString = "1.6578";
var n = new Date(0,0);
n.setMinutes(+decimalTimeString * 60);
var result = n.toTimeString().slice(0, 5);