To the Maya, keeping track of time was a sacred obligation. They believed that a unique retinue of gods ruled over each day. As the sun set each evening, the god who governed that day’s events passed the burden of ruling to the next god in line, who watched over the world until the sun set on his or her day of service. Similarly, a different god presided over each twenty-day week in the sacred Maya calendar called the tzolkin. In ever expanding cycles, a unique god ruled over the Maya months, years, decades, centuries, and millennia, only their cycles came in groupings of twenty. Twenty years (tuns) made a katun. Twenty katuns made a backtun. Each god imprinted on the cycle a unique characteristic that altered the nature of the day, and anyone born under the god’s watch. Knowing which gods ruled at a particular moment in time was essential to maintaining the delicate balance of life in the ancient Maya world.
Keeping track of the days, and which gods ruled them, helped the Maya determine when the rainy season was about to begin, for example, so they could prepare their fields for planting. They even calculated the most suitable time to go to war.
These same gods also oversaw the lives of individuals born on their days. The Maya believed each god bestowed upon a person special talents and personality traits. By understanding which god ruled the day of a person’s birth, the priests could determine what job a child was best suited to perform, for the community or whom he or she should marry.
The Maya created their complex calendar, often described as a series of interlocking wheels, in order to keep track of this endless, ever-changing collection of gods. he Maya calendar is considered by many to be one of their greatest achievements.