internal int GetDayOfWeek([Trusted] YearMonthDay yearMonthDay) => GetDayOfWeek(yearMonthDayCalculator.GetDaysSinceEpoch(yearMonthDay));
internal override int GetYearOfEra(YearMonthDay yearMonthDay) => yearMonthDay.Year;
internal override Era GetEra(YearMonthDay yearMonthDay) => era;
internal abstract int GetYearOfEra(YearMonthDay yearMonthDay);
internal abstract Era GetEra(YearMonthDay yearMonthDay);
internal bool IsInAyyamiHa(YearMonthDay ymd) => ymd.Month == Month18 && ymd.Day > DaysInMonth;
internal override Era GetEra(YearMonthDay yearMonthDay) => yearMonthDay.Year > 0 ? Era.Common : Era.BeforeCommon;
internal override int GetYearOfEra(YearMonthDay yearMonthDay) { int absoluteYear = yearMonthDay.Year; return(absoluteYear > 0 ? absoluteYear : 1 - absoluteYear); }