Origin of the Mesoamerican 260-Day Calendar

The sacred 260-day Mesoamerican calendar probably originated near a latitude of 15 degrees N, where there is a 260-day interval between transits of the zenithal sun. Archeological and faunal evidence favors an origin in the Pacific lowlands rather than in the highlands near Copan, Honduras, although Copan, which is located at the 15th parallel of latitude, later became the principal Mayan astronomical center.