JSFiddle - React, Tailwind, and code Playground

HTML

<div id="timer"></div>

JavaScript

setInterval(function() {
    var currentTime = new Date ( );    
    var currentHours = currentTime.getHours ( );   
    var currentMinutes = currentTime.getMinutes ( );   
    var currentSeconds = currentTime.getSeconds ( );
    currentMinutes = ( currentMinutes < 10 ? "0" : "" ) + currentMinutes;   
    currentSeconds = ( currentSeconds < 10 ? "0" : "" ) + currentSeconds;    
    var timeOfDay = ( currentHours < 12 ) ? "AM" : "PM";    
    currentHours = ( currentHours > 12 ) ? currentHours - 12 : currentHours;    
    currentHours = ( currentHours == 0 ) ? 12 : currentHours;    
    var currentTimeString = currentHours + ":" + currentMinutes + ":" + currentSeconds + " " + timeOfDay;
    document.getElementById("timer").innerHTML = currentTimeString;
}, 1000);