The Mayan Haab` calendar was kind of the opposite of that, 18x20 with 5 "nameless days" at the end. The nameless days were considered a dangerous, unlucky, and

The Mayan Haab` calendar was kind of the opposite of that, 18x20 with 5 "nameless days" at the end. The nameless days were considered a dangerous, unlucky, and very unparty time though.