code: private static ICommonsSet <LocalDate> _getEthiopianOrthodoxHolidaysInGregorianYear (final int nGregorianYear,
                                                                                         final int nEOMonth,
                                                                                         final int nEODay)
    {
      return CalendarHelper.getDatesFromChronologyWithinGregorianYear (nEOMonth,
                                                                       nEODay,
                                                                       nGregorianYear,
                                                                       CopticChronology.INSTANCE);
    }
docs: Returns a set of gregorian dates within a gregorian year which equal the
  Ethiopian orthodox month and day. Because the Ethiopian orthodox year
  different from the gregorian there may be more than one occurrence of an
  Ethiopian orthodox date in an gregorian year.
  
  @param nGregorianYear
  @param nEOMonth
  orthodox month
  @param nEODay
  orthodox day
  @return List of gregorian dates for the Ethiopian orthodox month/day.