An illustration depicting an ancient Mexican calendar. The Maya and Aztec calendars are the most familiar of the Mexican calendars, but similar ones were used by other cultures. Common to all Mesoamerican cultures was the 260-day ritual calendar that had no confirmed correlation to astronomical or agricultural cycles. These were used in combination with a separate 365-day calendar to create a 52-year cycle known as a calendar round.Artist: A. de Leon y Gama; Restoration: Garrondo/Lise Broer