how to get hours from timestamp in javascript code example

Example 1: javascript get hour from date

var myDate = new Date(2019, 11, 24, 10, 33);
var hour = myDate.getHours();

Example 2: javascript get 1 hour from now

Date.prototype.addHours = function(h) {
  this.setTime(this.getTime() + (h*60*60*1000));
  return this;
}