JSFiddle - React, Tailwind, and code Playground
HTML
<div id=test>0.0</div>
JavaScript
var xElement = null;
var startTime = new Date();
xElement = document.getElementById("test");
var Interval = window.setInterval(startWatch, 17);
function startWatch(){
var currentTime = new Date();
xElement.innerHTML = currentTime - startTime;
}