docs: private String getFormattedDate(int dateTimeFormat) {
  
          DateFormat df;
          String result;
          if (isWholeDay()) {
              df = DateFormat.getDateInstance(dateTimeFormat, m_series.getLocale());
              result = df.format(getStart());
              if (getLastDay().after(getStart())) {
                  result += DATE_SEPARATOR + df.format(getLastDay());
              }
          } else {
              df = DateFormat.getDateTimeInstance(dateTimeFormat, DateFormat.SHORT, m_series.getLocale());
              result = df.format(getStart());
              if (getEnd().after(getStart())) {
                  if (isMultiDay()) {
                      result += DATE_SEPARATOR + df.format(getEnd());
                  } else {
                      df = DateFormat.getTimeInstance(DateFormat.SHORT, m_series.getLocale());
                      result += DATE_SEPARATOR + df.format(getEnd());
                  }
              }
          }
  
          return result;
      }