Source: rookie tutorial
<script>
function startTime(){
var today=new Date();
var h=today.getHours();
var m=today.getMinutes();
var s=today.getSeconds();// add a '0' before the number less than 10
m=checkTime(m);
s=checkTime(s);
document.getElementById('txt').innerHTML=h+":"+m+":"+s;
t=setTimeout(function(){startTime()},500);
}
function checkTime(i){
if (i<10){
i="0" + i;
}
return i;
}
</script>
</head>
<body onload="startTime()">
<div id="txt"></div>
</body>
</html>
Put <div id="txt"></div> where it needs to be displayed, such as a navigation bar
