The tonalpohualli is a 260-day calendar used by the ancient Mesoamerican civilizations, particularly the Aztecs. It consists of 20 periods of 13 days, each associated with specific symbols and deities. This calendar was essential for agricultural, religious, and social activities, guiding rituals and ceremonies throughout the year. Each day in the tonalpohualli has its own significance, influencing the lives of individuals and communities. The calendar is often paired with the tzolkin, a 365-day solar calendar, to create a more comprehensive understanding of time. Together, these calendars reflect the intricate relationship between the Mesoamerican people and their environment.