The Solar Calendar
FIGURE 6. The Year 13 Reed on the Calendar Stone.
FIGURE 7. Greenstone fire serpent (xiuhcoatl) statuette. viewed from the side and from below. The snout of this beast has been broken off; in the profile photo the fire serpent is facing to the left, and you can still see three of his curved triangular teeth. Dumbarton Oaks Museum (PC.B.069). Photo by Justin Kerr © Dumbarton Oaks, Pre-Columbian Collection, Washington, DC.
FIGURE 8. The signs for the months of Ochpaniztli (left) and Tlacaxipehualizti (right) on folio 13r of the Matrícula de Tributos.
FIGURE 9. The sign for the month of Etzalcualiztli in Cell 15 of the Lienzo de Tlaxcala.
FIGURE 10. Cell 14 of the Lienzo de Tlaxcala.
In addition to the ritual calendar of 260 days, Central Mexicans (like many other people in Mesoamerica) kept track of a solar calendar. They referred to this cycle as the xiuhpohualli (“year count”). This cycle consisted of 360 days (which were given names taken from the cycle of the tonalpohualli) plus an additional 5 days at the end of the cycle which were unnamed (and therefore considered a dangerous period of time). The Central Mexican year began in the spring, corresponding to February or March in the Gregorian calendar. The exact correlation of the xiuhpohualli to the Gregorian calendar is unclear, because colonial sources on the precise dates are conflicting. This conflict may be an indication that different regions began their years on slightly different days. We saw above how each day in the tonalpohualli was given a name. Similarly, each year in the xiuhpohualli was named. Like the days of the tonalpohualli, these xiuhpohualli names consisted of a numeric value (indicated by one to thirteen dots) combined with one of four different glyphic signs: Rabbit, Reed, Flint, and House. The first year in the cycle was named 1 Rabbit, the second year 2 Reed, the third year 3 Flint—and so on until 52 years had passed (4 × 13) and the cycle began again.5
Since the years in the xiuhpohualli were named using the same glyphic system as the days in the xiuhpohualli, it is sometimes difficult to know whether a glyphic date refers to a solar year or to a day in the ritual calendar. Fortunately, year dates are often surrounded by a rectangular box, or cartouche. On the Calendar Stone, the 13 Reed date at the very top of the stone is surrounded by one of these rectangular cartouches, indicating that it represents a year (Figure 6).6 Another example of a cartouche-surrounded date can be found on the bottom of a greenstone fire serpent (xiuhcoatl) statue in the Dumbarton Oaks Museum in Washington. In Figure 7, you can see this glyphic date: Year 2 Reed.7
Just as the tonalpohualli was subdivided into trecenas, so too was the xiuhpohualli subdivided into smaller units. Every 360-day cycle was broken into 18 months of 20 days (18 × 20 = 360). In turn, each month was divided into four “weeks” of five days. Each month had its own name (represented by a different glyphic sign), and was connected to specific festivals. These cycles of months and weeks were used to organize a number of different aspects of Central Mexican life.
One example of this has to do with markets. In the capital city of Tenochtitlan-Tlatelolco there was a huge, permanent marketplace open every day. In smaller cities, however, markets were held periodically. One of the entries in Alonso de Molina’s 1555 Castilian to Nahuatl dictionary reads Feria de cinco en cinco dias. macultiáquiztli (“Fair held every 5 days. macultiáquiztli”), and another reads Ferias de veynte en veynte dias. cempoualtiáquiztli (“Fairs held every 20 days. cempoualtiáquiztli”).8 These entries suggest that the weeks and months of the solar calendar were used to organize a cycle of temporary market days.9
Another example concerns tribute payments. As recorded in the Matrícula de Tributos, the Aztecs demanded tribute payments from subject provinces every 80 days—that is, 4 times a year (4 × 80 = 360). As a result, four months in each solar year were associated with tribute payments (and again, correlating these dates to the Gregorian calendar is complicated, because colonial sources give conflicting information).10 These months (according to a sixteenth-century account written by Diego Durán) were:
- Tlacaxipehualizti (“Flaying of Men”): March 21-April 9
- Etzalcualiztli (“Eating Maize and Bean Porridge”): June 9-June 29
- Ochpaniztli (“Sweeping”): September 17-October 6
- Panquetzaliztli (“Raising of Banners”): December 6-January 1411
Glyphic signs for two of these months appear in the Matrícula de Tributos, on the page illustrating the tribute payments demanded from the province of Xoconochco. The month Tlacaxipehualizti is indicated with an image of the pointed headdress of Xipe Totec, the flayed god. The month Ochpaniztli (damaged) is indicated with an image of a broom made of long grasses (Figure 8). The province of Xoconochco was located in what is now Guatemala, and was the tribute province farthest from Tenochtitlan. The signs for Tlacaxipehualizti and Ochpaniztli (the first and third tribute months) probably indicate that Xoconochco only sent tribute to Tenochtitlan twice a year, given how long it would take to actually transport the required jaguar pelts, cacao beans, and multicolored feathers all the way from the Pacific coast to the Valley of Mexico.
The sign for the second tribute month, Etzalcualiztli, is shown in Cell 15 of the Lienzo de Tlaxcala (Figure 9). This scene depicts the death of Moctezuma II by stoning during an attack on the palace in Tenochtitlan where the Castilian and Tlaxcalan forces were holding the tlatoani captive. This month—whose name means “Eating Maize and Bean Porridge” in Nahuatl—is indicated by the drawing of a gourd bowl (the kind of vessel in which maize and bean porridge would have been eaten).12 According to the accounts of the conquistadors, the events shown in Cell 15 took place in late June 1520. This corresponds to what Diego Durán said about the month Etzalcualiztli: that it ran from June 9 to June 28.
If four of the months of the Central Mexican solar year were associated with tribute payments, all of them were dedicated to different deities and involved different festivals. (Remember that each of the thirteen-day trecenas in the tonalpohualli was also dedicated to a different supernatural). For example, the month just before Etzalcualiztli, called Toxcatl (“Dryness”) was dedicated to the god Tezcatlipoca (“Smoking Mirror”).13 This month was usually indicated by a bundle of dried plants. However, in Cell 14 of the Lienzo de Tlaxcala the month is indicated by the head of Tezcatlipoca himself, wearing his characteristic striped face paint (Figure 10). The main scene in Cell 14 shows the massacre of people celebrating the rites of Toxcatl by Pedro de Alvarado and his Castilian and Tlaxcalan warriors. According to European sources, this event took place in late May 1520—which again confirms what Durán said about the month of Toxcatl: that it ran from May 20 to June 8.
The 52-Year Cycle >
5 The 260-day tonalpohualli cycles did not receive their own name, and the days of the xiuhpohualli cycle were named according to the tonalpohualli count.
6 Umberger 1988, 348.
7 Vila Llonch 2009.
8 Molina 1555, 123r.
9 For more on Central Mexican markets, see Smith 2003, 106-112.
10 On the calendrical structure of Aztec tribute demands, see Gutiérrez et al. 2009, 61-62. Betty Brown, in a 1977 dissertation, argues that the system of “months” was a colonial creation. Elizabeth Hill Boone, citing Brown, is also wary (2007, 254-255). Part of the evidence Brown uses for her colonial invention theory, apart from conflicting colonial accounts, is that “there is no known evidence for the use of the Mexica monthly calendar before European Contact” (Brown 1977: vi). However, if the Matrícula de Tributos is a prehispanic document, then it does provide prehispanic evidence for this system of months (and for the symbols associated with each). Conflicting colonial accounts of the system of months may also be due to the existence of different, local calendar systems. Brown does provide a useful overview of sixteenth-century sources on the “months” of the xiuhpohualli (Brown 1977, 99-164).
11 The date correlations are those provided by Durán 1971, 467-68.
12 Chavero 1892, 37.
13 Klein 2001, 219-228.