1491_ New Revelations of the Americas Before Columbus - Charles C. Mann [205]
The Mesoamerican calendar also tied together linear and cyclical time, but more elaborately. In its most fully developed form, at the height of Maya power, it consisted of three separate but interrelated calendars: a sacred tally known as the tzolk’in; the haab, a secular calendar based, like the Western calendar, on the rotation of the sun; and the Long Count, a system that, among other things, linked the other two.
The sacred calendar is both the calendar most dissimilar to Western calendars and the most important culturally. Each day in the tzolk’in had a name and a number, in somewhat the same way that one might refer to, say, “Wednesday the 15th.” In the Western calendar, the day names (e.g., Wednesday) run through cycles of seven, making weeks, and the day numbers (e.g., the 15th) run through cycles of 28, 30, or 31, making months. The tzolk’in used the same principle, but with less variation in the lengths of the cycles; it had a twenty-day “week” of named days and a thirteen-day “month” of numbered days. The analogy I am drawing is imprecise; what I am describing as the tzolk’in “week” was longer than the “month.” But just as Thursday the 16th follows Wednesday the 15th in the Christian calendar, 10 Akbal would follow 9 Ik in the tzolk’in. (The Maya had a twenty-day “week” in part because their number system was base-20, instead of the base-10 in European societies.)
Because the tzolk’in was not intended to track the earth’s orbit around the sun, its inventors didn’t have to worry about fitting their “weeks” and “months” into the 365 days of the solar year. Instead they simply set the first day of the year to be the first day of the twenty-day “week” and the thirteen-day “month,” and let the cycle spin. In the language of elementary school mathematics, the least common multiple (the smallest number that two numbers will divide into evenly) of 13 and 20 is 260. Hence, the tzolk’in had a length of 260 days.
In the Western calendar, a given combination of named and numbered days, such as Wednesday the 15th, will occur a few times in a calendar year. For instance, in 2006 the 15th of the month falls on Wednesday three times, in February, March, and November; in 2007 Wednesday the 15th occurs just once, in August. The irregular intervals are due to the differing lengths of the months, which throw off the cycle. In the tzolk’in, every “month” and every “week” are the same length. As a result, “Wednesday the 15th”—or 1 Imix, to give a real example—in the tzolk’in recurs at precise intervals; each is exactly 13 × 20 or 260 days apart.
Many researchers believe the movements of Venus, which Mesoamerican astronomers tracked carefully, originally inspired the tzolk’in. Venus is visible for about 263 consecutive days as the morning star, then goes behind the sun for 50 days, then reappears for another 263 days as the evening star. It was a powerful presence in the heavens, as I noted in Chapter 8, and a calendar based on its celestial trajectory would have shared some of that power. Within the sacred year, every day was thought to have particular characteristics, so much so that people were often named after their birth dates: 12 Eb, 2 Ik, and so on. In some places men and women apparently could not marry if they had the same name day. Days in the tzolk’in had import for larger occasions, too. Events from ceremonies to declarations of war were thought to be more likely to succeed if they occurred on a propitious day.
The Mesoamerican calendar was both more complex and more accurate than the European calendars of the same period. It consisted of a 365-day secular calendar, the haab (right), much like contemporary European calendars. The haab was tied to the second, sacred calendar, the tzolk’in (left), which was unlike any Western