Trecena

Trecena is the name of a thirteen -day time unit, which was used in several pre-Columbian Mesoamerican calendar systems. Even if the Trecena is today mostly associated with the Aztec culture, this time unit was used in the calendars of the Maya, Zapotec, Mixtec, Olmec, and other cultures. The term Trecena is derived from the Spanish word for thirteen ( trece ).

A Trecena represents one twentieth of the 260 -day ceremonial calendar of the Aztecs tonalpohualli dar. Each of the twenty Trecenas is associated with one or more Aztec deities.