JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/clockpicker/0.0.7/bootstrap-clockpicker.min.css">
<script src="https://cdnjs.cloudflare.com/ajax/libs/clockpicker/0.0.7/bootstrap-clockpicker.min.js"></script>

      <div class="panelsadd">
       <button type="button" class="btn btn-default add_btn" name="add_btn">追加する</button>
      </div>
                          <div class="panel panel-default panels">
                            <div class="panel-body">
                               <div class="form-group">             
                                  <label>時間</label>
                                  <div>
                                    <input type="text" class="form-control clockpicker" name="time[]">
                                  </div>
                              </div> 

                              <div class="date_box">
                                  <label>日程</label>
                                  <div>
                                    <input class="datepicker dateadd" type="text" name="mt_date[]">
                                  </div>
                              </div>
                           </div>                                                                                                                                                                                          
                       </div>

JavaScript

var clone = $('.panels:last');
$('.panelsadd').on('click', '.add_btn', function(){
                $('.panels:last').after(clone.clone());              
                $('.panels:last input.clockpicker').clockpicker();
});
//clockpicker部分
$(function() {
       $('.clockpicker').clockpicker();
     });