Mesoamerican Long Count calendar Mesoamerican Long Count calendar The Mesoamerican Long Count calendar is a non-repeating, vigesimal (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 (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 a mythical creation date that corresponds to August 11, 3114 BCE in the Proleptic Gregorian calendar. The Long Count calendar was widely used on monuments. The two most widely used calendars in pre-Columbian Mesoamerica, were the 260-day Tzolk'in
Adoption of the Gregorian calendar calendar) and Myanmar (Burmese calendar), and other countries use a modified version of the Gregorian calendar, including Thailand (Thai solar calendar), Japan (Japanese calendar), North Korea (North Korean calendar) and Taiwan (Minguo calendar). While many religious organizations reckon their liturgical year by the Gregorian civil calendar, others have retained their own calendars. Alternative calendars are used in many regions of the world today to mark cycles of religious and astrological events. Use of different calendars had potential to cause confusion between contemporaries. For example, it is related that one of the contributory factors for Napoleon's victory at the Battle of