JSFiddle - React, Tailwind, and code Playground

JavaScript

var date1 = '2013-09-17 11:59:00 PM';
var date2 = '2013-09-18 12:00:00 AM';

var d1msecs = new Date(date1).getTime();
console.log(d1msecs);
var d2msecs = new Date(date2).getTime();
console.log(d2msecs);

var avgTime = (d1msecs + d2msecs) / 2;
console.log(avgTime);

var result = new Date(avgTime);
alert(result);