JSFiddle - React, Tailwind, and code Playground

JavaScript

var a = "10:20:45";
    var b = "5:10:10";
    
    var timeA = new Date();
    timeA.setHours(a.split(":")[0],a.split(":")[1],a.split(":")[2]);
    timeB = new Date();
    timeB.setHours(b.split(":")[0],b.split(":")[1],b.split(":")[2]);
    // var x= "B is later than A";
   
    if(timeA>timeB) 
    {
    alert("A is large");
    }
    else{
    alert("B is large");
    }