Aztec Calendar Facts

Mexica/Aztec Calendar Systems | The Civil Calendar
By by Dale Hoyt Palfrey

FACT: The solar year was the basis for the civil calendar by which the Mexicas (Aztecs) determined the myriad ceremonies and rituals linked to agricultural cycles.

The 18 month calendar with each month lasting only 20 days where each month was divided by four 5 day weeks. The year was rounded out to 365 days and then an addition of a five-day nemontemi(empty days).

The nemontemi was an omnious period marked by the cessation of normal activities and general abstinence. The correlation of dates in the Gregorian calendar is uncertain, although most authors on the subject affix the beginning of the Aztec year to early February.