code: public static JulianCalendar of(
          HistoricEra era,
          int yearOfEra,
          Month month,
          int dayOfMonth
      ) {
  
          return JulianCalendar.of(era, yearOfEra, month.getValue(), dayOfMonth);
  
      }
docs: /*[deutsch]
  <p>Erzeugt ein neues julianisches Kalenderdatum. </p>
  
  @param   era         either {@code HistoricEra.AD} or {@code HistoricEra.BC}
  @param   yearOfEra   year of era in range 1 until 999,999,999
  @param   month       month (1-12)
  @param   dayOfMonth  day of month (1-31)
  @return  new instance of {@code JulianCalendar}
  @throws  IllegalArgumentException in case of any inconsistencies
  @since   3.15/4.12