The Mayan Calendar

This is the Tzolkin calendar used by the Mayans. It counts in base 20 and combines 20 day names (orange) with 13 numbers (brown), giving 260 unique days. This calendar was used for religious purposes. The other two Mayan calendars were the Haab, with 360 days, for civil purposes and the "Long Count" (pink), with cycles up to days.