JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://ajax.googleapis.com/ajax/libs/jqueryui/1.11.4/jquery-ui.min.js"></script>
<link rel="stylesheet" href="https://ajax.googleapis.com/ajax/libs/jqueryui/1.11.4/themes/smoothness/jquery-ui.css">
<input type="text" id="date1">

JavaScript

$("#date1").datepicker({
    changeMonth: true,
    changeYear: true,
    onSelect: function(dateText,inst) {
        if(dateText !== inst.lastVal){
            if (inst.lastVal == '') {
                alert("User has selected: "+dateText);
            } else {
                alert("User has change "+inst.lastVal+" to "+dateText)
            }
        }
    }
});