Format ABAP like timestamp in JavaScript

abap.js

Date.prototype.toABAPString = function () {
    let formatNumber = number => ("0" + number).slice(-2);
    return this.getFullYear() + formatNumber(this.getUTCMonth() + 1) + formatNumber(this.getUTCDate()) + formatNumber(this.getUTCHours()) + formatNumber(this.getUTCMinutes()) + formatNumber(this.getSeconds());
}