Simple jQuery UI Datepicker example

HTML

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.3/jquery.min.js"></script>
<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">
Date Picker on input field: <input type="text" id="date1" name="date1"/> <br/>

CSS

#ui-datepicker-div { font-size: 12px; }

JavaScript

var oldDate = Date;
Date = function (fake)
{
    if( ! fake ) return new oldDate('2017/02/02');

    return new oldDate(fake);
}
Date.prototype = oldDate.prototype;

$('#date1').datepicker({
    changeMonth: true,
    changeYear: true,
    showButtonPanel: true,
    dateFormat: "m/d/yy"
});