seconds to timestamp javascript code example

Example 1: javascript timestamp in seconds

const ts = () => Math.floor(new Date().getTime() / 1000);

Example 2: 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)