JSFiddle - React, Tailwind, and code Playground

HTML

<input type="button" value="Pause" onClick="paused=true" />
<input type="button" value="Resume" onClick="paused=false" />
<div id="time">Time</div>

JavaScript

paused = false;

setInterval(function(){
    if (paused) return;
    console.log('tick')
    var div = document.getElementById('time');
    div.innerHTML = (new Date()).toString()

}, 1000)