The calendar systems used in the ancient world reflect the agricultural, political and ritual needs characteristic of the societies in which they flourished. Astronomical observations to establish the winter and summer solstices were in use three to four millennia ago. The ancient Maya were accomplished observers of the sky.The ancient Maya had a fascination with cycles of time. The most commonly known Maya cyclical calendars are the Haab, the Tzolk’in, and the Calendar Round.The Classic Maya civilization of southern Mexico, Guatemala and Belize flourished in the fourth through tenth century CE. They were accomplished astronomers and crafted a fascinating calendar system.