The Calendar Round
The harmonization of the 260-day Tzolkin cycle and the 365-day Haab cycle was done by meshing them together to create the bigger calendar round cycle. The common factor between the two calendars is 18,980 days, which equals exactly seventy-three Tzolkins and fifty-two Haabs. Each day in a calendar round has a unique combination of the Tzolkin and Haab signs. Only after 18,980 days will the same Tzolkin and Haab combination be repeated. This cycle, of very close to fifty-two years, equates psychologically to the equivalent of our century.
The calendar round was longer than the average life span and was considered to be sufficient for day and date calculation for most civil purposes. If a person knew both the Tzolkin and Haab dates for a day, they would be pretty sure of their place in time. The synchronization of these two calendars was of extreme significance to the Maya, and much more important than having a fixed-year calendar. The reason for this is that many of the functions of the fixed-year calendar like accurately dating the equinoxes, the zenith passages of the sun, and eclipse cycles were already being performed by following the 260-day cycle. This meant they just didn't need it. Agricultural cycles were measured from these reference points and also in divisions of twenty-day periods from the first rain of the year, so the calendar round was sufficient for most purposes.
Significance of the Calendar Round
What the Maya liked in the calendar round was that everything came very exactly to a perfect moment of synchronization once every fifty-two years, creating a mathematical perfection that was very appealing to the Mayan mind. It was a predictable and useful way of measuring time for them and they celebrated the end of a calendar round by holding massive festivities. Entire new layers were often added to pyramids to remake them anew for the next fifty-two-year cycle. Great fires were set alight and sometimes all of the huts and wooden buildings the Maya lived in were burned as well. It was a time of great anticipation as they waited to see if the gods would grant them the grace of another fifty-two years.
On a personal level, the fifty-second birthday of a Maya was the point at which an individual was recognized as a true elder, having completed what was seen as an entire lifetime. They were then effectively reborn into a second life, though during the classic period, few would have been lucky enough to live this long. The calendar would be pretty remarkable if this was its totality, but for the Maya, this was just the beginning. In the next chapter we will explore their greatest achievement: the Long Count, the calendar that is famously scheduled to end on December 21, 2012.