JSFiddle - React, Tailwind, and code Playground

HTML

<p>Date: <input type="text" id="datepicker" /></p>
<input type="button" id="checkDate" value="CheckDate">

JavaScript

$(document).ready(function(){
    $( "#datepicker" ).datepicker();
    $('#checkDate').bind('click',function(){
        var myDAte = $('#datepicker').datepicker( "getDate" );
        var curDate = new Date();
        
        if(curDate>myDAte){
            alert('current date is high');
        }
        else{
            alert('selected date is low');
        }
    });
});