JQuery Number of days between two inputted dates

This counts the number of days between two dates entered via input. ~ Andrew Pougher

HTML

<input id="first" value="8/5/2012" placeholder="m/d/yyyy"/>
<input id="second" value="10/15/2012"/><hr>
<button id="btn">Show Days</button>
<div id="result"></div>
<hr>
<button id="btn1">Show Month Names</button>

JavaScript

var startDate = Date.parse("26/12/2018");
startDate = startDate.toString('dd-MM-yy');
var date = new Date(); 
var endDate = Date.parse(date);
alert(endDate);
var timeDiff = endDate - startDate;
daysDiff = Math.floor(timeDiff / (1000 * 60 * 60 * 24));
alert(daysDiff);