MonthCalendarSerializer

KSerializer for MonthCalendar - struct form with the five geometry fields plus the calendar the month is expressed in, written as an era number through CalendarSystemSerializer.

era is optional and defaults to Bikram Sambat, so a payload written by NepaliMonthCalendarSerializer decodes here as a Bikram Sambat month. That payload's daysFromStartOfWeekToFirstOfMonth is accepted and discarded: MonthCalendar derives it from firstDayOfMonth, so it is never written out and never read back.