Unearthed in 1790, the Aztec Calendar Stone is one of the most impressive artifacts recovered from the advanced civilization that ruled central Mexico for centuries, but it’s not actually a calendar.

The Aztecs, just like the Mayans, used three distinct calendars, which led to a very complex form of astrology being formed. This art associates a sign of the day, a sign of the month and a sign of ...

Ancient Aztec and Chinese calendar systems share so many similarities, it is unlikely they developed independently, according to the late David H. Kelley, whose paper on the subject was published ...