The two different Aztec calendars are the Tonalpohualli and the Xiuhpohualli. They differ mainly in their purpose and structure:
- The Tonalpohualli is a 260-day sacred calendar used primarily for religious and divinatory purposes. It consists of 20 periods of 13 days each, and it divides time among the gods. This calendar guides rituals, ceremonies, and the spiritual life of the Aztecs.
- The Xiuhpohualli is a 365-day solar calendar that aligns with the agricultural year. It consists of 18 months (called veintenas) with 20 days each plus an additional 5 unlucky days. This calendar primarily serves to organize agricultural activities and seasonal events.
Together, these calendars interlock to create a 52-year cycle called the Calendar Round.
