Mesoamerican architecture there is no evidence that this phenomenon was the result of a purposeful design intended to commemorate the equinoxes. Much Mesoamerican architecture is also aligned to roughly 15° east of north. Vincent H Malmstrom has argued that this is because of a general wish to align the pyramids to face the sunset on August 13, which was the beginning date of the Maya Long Count calendar. However, recent research has shown that the earliest orientations marking sunsets on August 13 (and April 30) occur outside of the Maya area. Their purpose must have been to record the dates separated by
Mesoamerican calendars (year count) and "tonalpohualli" (day count) respectively. The Veintena was called "metztli" (moon), and the five unlucky days at the end of the solar year were called "nemontemi". Other calendar cycles were also recorded, such as a lunar calendar, as well as the cycles of other astronomical objects, most importantly Venus. Mesoamerican calendars Mesoamerican calendars are the calendrical systems devised and used by the pre-Columbian cultures of Mesoamerica. Besides keeping time, Mesoamerican calendars were also used in religious observances and social rituals, such as for divination. The existence of Mesoamerican calendars is known as early as ca. 500 BCE, with