JSFiddle - React, Tailwind, and code Playground

JavaScript

var from_date = new Date(2012, 6, 28); // jan = 0, dec = 11
var to_date = new Date(2012, 6, 28);

var X = 1;
var Y = 5;

from_date.setDate(from_date.getDate() + X);
to_date.setDate(to_date.getDate() + Y);

alert(from_date + "\n" + to_date);