JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE html>
<html>
    
    <head>
        <meta content="text/html; charset=UTF-8" http-equiv="Content-Type" />
        <title>setInterval/clearInterval example</title>
        <script type="text/javascript">
            var nIntervId;

            function updateTime() {
                nIntervId = setInterval(flashTime, 1000*2);
            }

            function flashTime() {
                var now = new Date();
                var h = now.getHours();
                var m = now.getMinutes();
                var s = now.getSeconds();
                var time = h + ' : ' + m + ' : ' + s;
                $('#my_box1').html(time);
            }

            $(function() {
                updateTime();
            });
        </script>
    </head>
    
    <body>
        <div id="my_box1">
            <p>Hello World</p>
        </div>
    </body>

</html>