Mesoamerican Long Count calendar

Mesoamerican Long Count calendar - Page 1

The Mesoamerican Long Count calendar is a non-repeating, vigesimal (base-20) calendar used by several Mesoamerican cultures, most notably the Maya. For this reason, it is sometimes known as the Maya (or Mayan) Long Count calendar. Using a modified vigesimal tally, the Long Count calendar identifies a day by counting the number of days passed since August 11, 3114 BCE (Gregorian).^[1] Because the Long Count calendar is non-repeating, it was widely used on monuments.

Background

Among other calendars devised in pre-Hispanic Mesoamerica, two of the most widely used were the 365-day solar calendar (Haab' in Mayan) and the 260-day ceremonial calendar, which had 20 periods of 13 days. This 260-day calendar was known as the Tzolk'in to the Maya and tonalpohualli to the Aztecs.

The Haab' and the Tzolk'in calendars identified and named the days, but not the years. The combination of a Haab' date and a Tzolk'in date was enough to identify a specific date to most people's satisfaction, as such a combination did not occur again for another 52 years, above general life expectancy.