Ancient history

What civilization created an accurate calendar between A.D. 300 and 900?

The Maya civilization created an accurate calendar between A.D. 300 and 900. The Mayan calendar was a complex system of timekeeping that was used by the Maya people of pre-Columbian Mesoamerica. It was one of the most accurate calendars in the ancient world, and it was used for a variety of purposes, including religious rituals, agricultural planning, and tracking the movement of the stars.