if you take in to consideration how the Mayan handled the 1/4 day then they could have handled Ophiuchus as the 1/4 day.
most calendars are repetitive like you can use a 1995 calender for 2006 that is 11 years
then some calendars have 366 days there are some links that will show what I am talking about.
now say the Mayan calendar is like these repetitive calendars and they are exactly the same after this point in time they can go back to the beginning so in stead of carving Identical calendars they were intelligent enough to say hay let us use the same one.
and the calendar is not the end some people think it is but it is just a reboot.
The Haab' was the Maya solar calendar made up of eighteen months of twenty days each plus a period of five days ("nameless days") at the end of the year known as Wayeb' (or Uayeb in 16th C. orthography). Bricker (1982) estimates that the Haab' was first used around 550 BCE with the starting point of the winter solstice.
The Haab' month names are known today by their corresponding names in colonial-era Yukatek Maya, as transcribed by 16th century sources (in particular, Diego de Landa and books such as the Chilam Balam of Chumayel). Phonemic analyses of Haab' glyph names in pre-Columbian Maya inscriptions have demonstrated that the names for these twenty-day periods varied considerably from region to region and from period to period, reflecting differences in the base language(s) and usage in the Classic and Postclassic eras predating their recording by Spanish sources.
Each day in the Haab' calendar was identified by a day number in the month followed by the name of the month. Day numbers began with a glyph translated as the "seating of" a named month, which is usually regarded as day 0 of that month, although a minority treat it as day 20 of the month preceding the named month. In the latter case, the seating of Pop is day 5 of Wayeb'. For the majority, the first day of the year was 0 Pop (the seating of Pop). This was followed by 1 Pop, 2 Pop as far as 19 Pop then 0 Wo, 1 Wo and so on.
As a calendar for keeping track of the seasons, the Haab' was crude and inaccurate, since it treated the year as having 365 days, and ignored the extra quarter day (approximately) in the actual tropical year. This meant that the seasons moved with respect to the calendar year by a quarter day each year, so that the calendar months named after particular seasons no longer corresponded to these seasons after a few centuries. The Haab' is equivalent to the wandering 365-day year of the ancient Egyptians. Some argue that the Maya knew about and compensated for the quarter day error, even though their calendar did not include anything comparable to a leap year, a method first implemented by the Romans.http://www.hermetic.ch/cal_sw/idcal/idcal.htmhttp://www.timeanddate.com/calendar/rep ... country=27http://en.wikipedia.org/wiki/Maya_calendar