In addition to the sacred calendar found on the Sun Stone, the Aztecs relied on a 365-day agricultural
calendar. Like the Maya, the Aztecs accurately divided the time it takes for the earth to travel around
the sun. They named 18 months, each with four five-day weeks. Market days were held once each week. The
five remaining days, as in the Maya calendar, were considered unlucky.
Once every 52 years, the sacred calendar and the agricultural calendar ended at the same time.
This was a cause for special ceremonies. The Aztec believed it was during this occurrence that
the end of world could come. All fires in the city capital were extinguished, sacrifices were made,
and astronomers watched for the appearance of a cluster of stars, now known as the Pleiades, that would
indicate to the Aztecs that the earth would not end.
In what other way did the Aztec record their legends?
Aztec scribes wrote books, or codices, to keep track of history and their calendar. The trained scribes wrote
in symbols called glyphs that were painted on sheets of bark or deerskin. The sheets were then folded
to form a book. While most of the Aztec codices were destroyed by the Spanish, sixteenth-century historians
and priests preserved some of them. These codices depict aspects of daily life and record legends about the
The Codex Borbonicus shows the Aztec creation god (Ometecuhtli) and goddess (Omecihuatl). According
to Aztec legend, these first Aztec deities had four sons whose rivalry resulted in the creation and
destruction of four worlds. Aztecs believed they lived in the fifth world, which was created when the
four sons were reunited. Surrounding the god and goddess on this page are symbols for the tonalpohualli,
or day count of the sacred calendar. The twenty signs shown in the glyphs are combined with the numbers 1 through
13, shown by the dots in the codex.
Credits: Aztec Calendar Stone © Kimball Morrison/South American Pictures;
Codex Borbonicus © J.P. Courau/Explorer/Gamma.
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