如何禁用引导程序时间选择器中的按钮

我使用的是adminLTE模板，从这个模板我使用一个名为时间选择器的表单字段，从这里我点击递减按钮，它也将是递减时间，就像递增按钮一样，但为了我的方便，假设现在时间4.15意味着，现在我已经在时间等于2.15时点击了递减按钮，这次我想取消点击递减按钮，我该怎么做？请帮帮我，这里我只显示递减函数：

 <script>
      $(function () {
      //Date range picker with time picker
      $('#reservationtime').daterangepicker({timePicker: true, timePickerIncrement: 30, format: 'MM/DD/YYYY h:mm A'});
      //Timepicker
      $(".timepicker").timepicker({
      showInputs: false
      });
      });
      </script>
      
      
      <script>
        decrementHour: function() {
      if (this.showMeridian) {
        if (this.hour === 1) {
          this.hour = 12;
         
        } else if (this.hour === 12) {
          this.hour--;
          return this.toggleMeridian();
        } else if (this.hour === 0) {
          this.hour = 11;
          
          return this.toggleMeridian();
        } else {
          this.hour--;
        }
      } else {
        if (this.hour === 0) {
          this.hour = 23;
        } else {
          this.hour--;
        }
      }
      this.update();
    },
        
      </script>  

    <div class="bootstrap-timepicker">
                                        <div class="bootstrap-timepicker-widget dropdown-menu">
                                        <table>
                                        <tbody><tr><td><a href="#" data-action="incrementHour"><i class="glyphicon glyphicon-chevron-up"></i></a></td><td class="separator">&nbsp;</td><td><a href="#" data-action="incrementMinute"><i class="glyphicon glyphicon-chevron-up"></i></a></td><td class="separator">&nbsp;</td><td class="meridian-column"><a href="#" data-action="toggleMeridian"><i class="glyphicon glyphicon-chevron-up"></i></a></td></tr><tr><td><span class="bootstrap-timepicker-hour">10</span></td> <td class="separator">:</td><td><span class="bootstrap-timepicker-minute">15</span></td> <td class="separator">&nbsp;</td><td><span class="bootstrap-timepicker-meridian">AM</span></td></tr><tr><td><a href="#" data-action="decrementHour"><i class="glyphicon glyphicon-chevron-down"></i></a></td><td class="separator"></td><td><a href="#" data-action="decrementMinute"><i class="glyphicon glyphicon-chevron-down"></i></a></td><td class="separator">&nbsp;</td><td><a href="#" data-action="toggleMeridian"><i class="glyphicon glyphicon-chevron-down"></i></a></td></tr>
                                        </tbody>
                                        </table>
                                        </div>
                                        <div class="form-group">
                                          <div class="input-group" style="margin-right: 14px;margin-left: 14px">
                                            <input type="text" class="form-control timepicker" id="start_time" name="start_time">
                                            <div class="input-group-addon">
                                              <i class="fa fa-clock-o"></i>
                                            </div>
                                          </div>
                                        </div>
                                      </div>
                                    </div>