JSFiddle - React, Tailwind, and code Playground
HTML
Date1: <input type="date" id="date1" value="2013-01-08">
<br>
Date2:<input type="date" id="date2" value="2013-01-09">
<button> GEt Difference</button>
JavaScript
$("button").click(function(){
var date1 = parseInt( $('#date1').val());
alert(date1);
var date2 = parseInt($('#date2').val());
var diff = Math.round((date1 - date2 ) / 1000 / 60 / 60 / 24);
alert(diff);
return diff;
})