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
Mesoamerican chronology 850. Normally, the Classic period in Mesoamerica is characterized as the stage in which the arts, science, urbanism, architecture, and social organization reached their peak. This period was also dominated by the influence of Teotihuacan throughout the region, and the competition between the different Mesoamerican states led to continuous warfare. This period of Mesoamerican history can be divided into three phases. Early, from 250 to 550 CE; Middle, from 550 to 700; and Late, from 700 to 900. The early Classic period began with the expansion of Teotihuacan, which led to its control over the principal trade routes of northern