Mesoamerican Long Count calendar
Calendar used by several pre-Columbian Mesoamerican cultures / From Wikipedia, the free encyclopedia
The Mesoamerican Long Count calendar is a non-repeating base-20 and base-18 calendar used by several pre-Columbian Mesoamerican cultures, most notably the Maya. For this reason, it is often known as the Maya Long Count calendar. Using a modified vigesimal tally, the Long Count calendar identifies a day by counting the number of days passed since a mythical creation date that corresponds to August 11, 3114 BCE in the proleptic Gregorian calendar.[lower-alpha 1] The Long Count calendar was widely used on monuments.