JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.2.4/jquery.min.js"></script>
<link rel="stylesheet" href="https://ajax.googleapis.com/ajax/libs/jqueryui/1.11.4/themes/smoothness/jquery-ui.css">
<script src="https://ajax.googleapis.com/ajax/libs/jqueryui/1.11.4/jquery-ui.min.js"></script>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css">
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/js/bootstrap.min.js"></script>
<div class="container-fluid">
  <form>
    <div class="form-group">
      <label>This is a datepicker with input-group</label>
      <div class="input-group">
	<span class="input-group-addon"><i class="glyphicon glyphicon-calendar"></i></span>
	<input type="text" class="datepicker form-control">
      </div>
    </div>
  </form>

  <button id="opendialog" type="button" class="btn btn-primary">
    open dialog
  </button>
</div>

<div id="mydialog" class="modal fade" role="dialog">
  <div class="modal-dialog">
    <div class="modal-content">
      <div class="modal-header">
	<button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span></button>
      </div>
      <div class="modal-body">
	<form>
	  <div class="form-group">
            <label>This is a datepicker with input-group on modal</label>
            <div class="input-group">
              <span class="input-group-addon"><i class="glyphicon glyphicon-calendar"></i></span>
              <input type="text" class="datepicker form-control">
            </div>
	  </div>
	</form>
      </div>
    </div>
  </div>
</div>

CSS

.modal .input-group .form-control { z-index: 1060; }

JavaScript

$(function() {
	$('.datepicker').datepicker();
  $('#opendialog').click(function() {
		$('#mydialog').modal({backdrop:false,escape:false});
	});
});