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 Long Count calendar the GMT correlation is historical, astronomical and archaeological: Historical: Calendar Round dates with a corresponding Julian date are recorded in Diego de Landa's "Relación de las cosas de Yucatán" (written circa 1566), the Chronicle of Oxcutzkab and the books of Chilam Balam. De Landa records a date that is a Tun ending in the Short Count. Oxkutzcab contains 12 Tun endings. Bricker and Bricker find that only the GMT correlation in consistent with these dates. The Book of Chilam Balam of Chumayel contains the only colonial reference to classic long-count dates. The Julian calendar date of 11.16.0.0.0 confirms the GMT