Well, as a proud Mexican I know a thing or two about this madness that involves the Mayan calendar. For the Mayans the number twenty was very important, indeed their numerical system is based in the number twenty (I case you didn't know Mayans still exist in the south of Mexico). The Mayans had two calendars, one of 260 days for ritual purposes and another of 365 days (they really were excellent astronomers, the calendar was pretty accurate for that time). The calendar of 365 days consisted of 18 months with 20 days each, the final five days of the year were considered as "unlucky days" and didn't figure in any month.
I hope this information helps someone his search for the meaning of the hint, and if that is not the case, at least you know something more about the Mayan culture
