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
San Andrés (Mesoamerican site) suggest that writing among the Olmec was sacred and was closely tied to ritual activities.” The most important find was a fist-sized ceramic cylinder seal, likely used to print cloth. When rolled out, the seal shows two speech scrolls emanating from a bird, followed directly by a number of design elements enframing what has been interpreted as logograms for “king (sideways U shape),” "3 (three dots, according to the Mesoamerican bar and dots numbering system),” and “Ajaw (from the sacred 260-day calendar)", a designation used for both a calendar date and, in keeping with Mesoamerican custom, the name of an