The significance of the Mayan civilization's calendar lies in its intricate and sophisticated understanding of time and astronomy. The Maya developed the Tzolk'in (a 260-day calendar) and the Haab' (a 365-day solar calendar), which were interlocked to form a 52-year Calendar Round. This system was crucial for agricultural planning, religious rituals, and social organization. The Maya's calendrical calculations were remarkable for their accuracy, reflecting their advanced astronomical knowledge. The calendar not only dictated daily life but played a pivotal role in the broader cosmology of the Maya, linking human activities with celestial events.