clock
vanila js clock
HTML
<h1></h1>
CSS
h1{
color:#fff;
background:#333;
}
JavaScript
function clock(){
var time = new Date();
hour=time.getHours()
minutes= time.getMinutes()
seconds= time.getSeconds()
document.querySelector('h1').innerHTML= hour +" : "+ minutes +" : "+seconds;
}
setInterval(clock,1000);