JSFiddle - React, Tailwind, and code Playground

HTML

<iframe id="iframe"></iframe>

JavaScript

var first = new Date (2000,00,01);
var now = new Date();
var html = Math.floor((now.getTime() - first.getTime())/(1000*60*60*24));
document.getElementById('iframe').src= 'http://site.ru/'+html+'.html';