docs: @Override
      public Calendar convertDateStringToCalendar(String dateStr) {
          Calendar calendar = null;
          if (dateStr != null) {
              calendar = Calendar.getInstance();
              calendar.set(Integer.parseInt(dateStr.substring(6, 10)), Integer.parseInt(dateStr.substring(0, 2)) - 1,
                      Integer.parseInt(dateStr.substring(3, 5)));
          }
          return calendar;
      }