JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://eternicode.github.io/bootstrap-datepicker/bootstrap-datepicker/css/datepicker.css">
<script src="http://eternicode.github.io/bootstrap-datepicker/bootstrap-datepicker/js/bootstrap-datepicker.js"></script>
<link rel="stylesheet" href="http://netdna.bootstrapcdn.com/twitter-bootstrap/2.3.2/css/bootstrap-combined.min.css">
<input type="text" id="datepicker" />

JavaScript

var today = new Date();
var lastDate = new Date(today.getFullYear(), today.getMonth() + 1, 0);
$("#datepicker").datepicker({
    startDate: today,
    endDate: lastDate,
    
});

var counter=0;

$("#datepicker").change(function(){
    var date1 = $("#datepicker").datepicker('getDate');
date1=date1.getDate();


if(today.getDate() != date1)
{
    if(counter%2==0)
	alert("please select current date");
}
counter++;
});