how to create a generique date format in js code example

Example 1: format date js

const t = new Date();
const date = ('0' + t.getDate()).slice(-2);
const month = ('0' + (t.getMonth() + 1)).slice(-2);
const year = t.getFullYear();
const hours = ('0' + t.getHours()).slice(-2);
const minutes = ('0' + t.getMinutes()).slice(-2);
const seconds = ('0' + t.getSeconds()).slice(-2);
const time = `${date}/${month}/${year}, ${hours}:${minutes}:${seconds}`;

output: "27/04/2020, 12:03:03"

Example 2: javascript date format mm/dd/yyyy

var date_format = new Date();

document.write(innerHTML = date_format.getMonth()+'/'+ date_format.getDate()+'/'+date_format.getFullYear());