JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://cdnjs.cloudflare.com/ajax/libs/mootools/1.3.2/mootools-yui-compressed.js"></script>
<script src="https://raw.github.com/monkeyphysics/mootools-datepicker/master/datepicker.js"></script>
<link rel="stylesheet" href="https://raw.github.com/monkeyphysics/mootools-datepicker/master/datepicker.css">
<label>Datepicker starting at and allowing no value:</label>
<input name='date_allow_empty' type='text' value='' class='date picker' />
<div id="invokeDP"></div>

JavaScript

var dp = new DatePicker('.picker', {
  pickerClass: 'datepicker ',
  allowEmpty: true,
    toggleElements: ['invokeDP']
});