As mentioned in the overview article, the Calendar Round is the combination of the cyclical Tzolkin and Haab calendars that starts over every 52 years. Like with the Haab and Tzolkin calendars by themselves, a common way to visually explain the Calendar Round is by representing the calendars as interlocking gears.
With other Mesoamerican cultures, the Calendar Round was the longest length of time they recorded. This was not the case with the Maya, however, who also used the non-repeating Long Count -- which could be used to count beyond the 52 years of Calendar Round.
How Calendar Round Dates are Expressed
The Haab and Tzolkin dates are written today as a pair of dates. For example, the day on which the Tzolkin date 13 Ahau and the Haab date 8 Xul both fall is simply referred to as 13 Ahau 8 Xul. And once it occurs, a pairing of dates won’t occur again until 52 years have gone by.
Within the 52-year cycle, the calendars complete their own cycles at rates independent of each other. The Haab repeats 52 times and the Tzolkin repeats 73 times before the two calendars can meet up again to begin a new Calendar Round.
The Tzolkin date that fell on 0 Pop of the Haab was called the “year bearer.” The “characteristics” of a Tzolkin date that occurred on 0 Pop were thought to influence all the days of the Haab.
With the way that the calendars were set up, only 4 named days out of the 20 named days of the Tzolkin could ever occur on 0 Pop. In the Classic period, the 4 days -- known as “year bearers” -- were Akbal, Lamat, Ben and Etz’nab*. Taking into account the 13 numbers that are part of the Tzolkin, 52 unique Tzolkin dates could occur as “year bearers” (13 x 4 = 52). After 52 years, this sequence of year bearers started over.
Here’s a sample of the pattern of year bearer dates as they occurred: 1 Akbal, 2 Lamat, 3 Ben, 4 Etz’nab, 5 Akbal, 6 Lamat, 7 Ben, 8 Etz’nab, 9 Akbal, 10 Lamat, 11 Ben, 12 Etz’nab, 13 Akbal, 1 Lamat…
*These four days sometimes varied by region, as in the center of the Maya Lowlands, the days were Ik, Manik, Eb and Caban in the Classic Period. By the time of the Conquistadors, the days had become Kan, Muluc, Ix and Cauac.
“A Forest of Kings”; Linda Schele, David Friedel; 1990
“The Ancient Maya”; Robert J. Sharer, Loa P. Traxler; 2006
“Yaxchilan: The Design of an Maya Ceremonial City” Carolyn Elaine Tate; 1992