JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8/themes/dot-luv/jquery-ui.css">
<script src="https://code.jquery.com/jquery-1.11.3.js"></script>
<script src="https://code.jquery.com/ui/1.11.4/jquery-ui.js"></script>
<p>Date: <input type="text" id="datepicker"></p>

JavaScript

$("#datepicker").datepicker({
        beforeShowDay: function(date) {
            return [date.getDay() == 5];
        }
    });