The Aztec Calendar is a fascinating ancient timekeeping system used by the Aztec civilization in central Mexico. It consists of two main cycles: a 260-day ritual calendar called the Tonalpohualli and a 365-day solar calendar known as the Xiuhpohualli. Together, these cycles create a 52-year period called a "Calendar Round," which was essential for agricultural, religious, and social events. The calendar is often represented by a large stone disk, intricately carved with symbols and images of various deities and cosmic elements. This stone, known as the Sun Stone, reflects the Aztecs' deep understanding of astronomy and their belief in the cyclical nature of time, emphasizing the importance of harmony between humans and the universe.