JSFiddle - React, Tailwind, and code Playground

JavaScript

(function(){
var currentdate = new Date(); 
var datetime = currentdate.getHours();
if(datetime >=6 && datetime<15){
 // moning class
}
    else if(datetime >=15 && datetime<19){
 // evening classes
}
else{
 // night class
}
alert(datetime)
}());