The first, known as the Calendar Round, was based on two overlapping annual cycles: a 260-day sacred year and a 365-day secular year. Under this system, each day was assigned four pieces of identifying information: a day number and day name in the sacred calendar and a day number and month name in the secular calendar. Every 52 years counted as a single interval, or Calendar Round. After each interval the calendar would reset itself like a clock.
The Maya strongly believed in the influence of the cosmos on daily life. Consequently, Mayan knowledge and understanding of celestial bodies was advanced for their time: For example, they knew how to predict solar eclipses. They also used astrological cycles to aid in planting and harvesting and developed two calendars that are as precise as those we use today.
achievements- astronomy, agriculture, engineering and communications
