JSFiddle - React, Tailwind, and code Playground

HTML

<div id="out"></div>

JavaScript

var bdate_str = '2015-03-30 02:00:00'

var now = new Date();
var bdate = new Date(bdate_str.replace(' ','T'));
bdate.setMinutes(bdate.getMinutes() + now.getTimezoneOffset());
var age = now.getUTCFullYear() - bdate.getFullYear();
var m = now.getUTCMonth() - bdate.getMonth();
var d = now.getUTCDate() - bdate.getDate();
var h = now.getUTCHours() - bdate.getHours();
var i = now.getUTCMinutes() - bdate.getMinutes();
var s = now.getUTCSeconds() - bdate.getSeconds();
if (m < 0 || d < 0 || h < 0 || i < 0 || s < 0) age--;

out.innerText = age;