The Mesoamerican Calendar is a complex and sophisticated system used by various pre-Columbian cultures, notably the Maya and Aztec, to track time through a combination of interlocking cycles, including the 260-day Tzolk'in and the 365-day Haab'. These calendars not only served practical purposes in agriculture and rituals but also reflected the intricate cosmological and religious beliefs of these civilizations, emphasizing the cyclical nature of time and the universe.