JSFiddle - React, Tailwind, and code Playground

HTML

<body>
	<span id="time"></span>
</body>

JavaScript

var e = document.getElementById("time");
window.onload = setInterval(
        function () { 
        var now = new Date();
        var day = ("0" + now.getDate()).slice(-2);
        e.innerHTML = day;
	},1000);