Xiuhpōhualli

The xiuhpōhualli (Nahuatl pronunciation: [ʃiʍpoːˈwalːi], from xihuitl + pōhualli) is a 365-day calendar used by the Aztecs and other pre-Columbian Nahua peoples in central Mexico. It is composed of eighteen 20-day "months," called veintenas or mētztli (the contemporary Nahuatl word for month) with a separate 5-day period at the end of the year called the nemontemi. Whatever name that was used for these periods in pre-Columbian times is unknown. Through Spanish usage, the 20-day period of the Aztec calendar has become commonly known as a veintena. The Aztec word for moon is mētztli, and this word is today to describe these 20-day periods, although as the sixteenth-century missionary and early ethnographer, Diego Durán explained:

In ancient times the year was composed of eighteen months, and thus it was observed by these Indian people. Since their months were made of no more than twenty days, these were all the days contained in a month, because they were not guided by the moon but by the days; therefore, the year had eighteen months. The days of the year were counted twenty by twenty.

The xiuhpōhualli calendar (in history known as the "vague year" which means no leap day) had its antecedents in form and function in earlier Mesoamerican calendars, and the 365-day count has a long history of use throughout the region. The Maya civilization version of the xiuhpōhualli is known as the haab', and 20-days period was the uinal. The Maya equivalent of nemontemi is wayeb'. In common with other Mesoamerican cultures the Aztecs also used a separate 260-day calendar (Classical Nahuatl: tonalpōhualli). The Maya equivalent of the tonalpōhualli is the tzolk'in. Together, these calendars would coincide once every 52 years, the so-called "calendar round," which was initiated by a New Fire ceremony.

Aztec years were named for the last day of the 18th month according to the 260-day calendar the tonalpōhualli. The first year of the Aztec calendar round was called 2 Acatl and the last 1 Tochtli. The solar calendar is connected to agricultural practices and holds an important place in Aztec religion, with each month being associated with its own particular religious and agricultural festivals. Each 20-day period starts on a Cipactli (Crocodile) day of the tonalpōhualli for which a festival is held. The eighteen veintena are listed below. The dates in the chart are from the early eyewitnesses, Diego Durán and Bernardino de Sahagún. Each wrote what they learned from Nahua informants. Sahagún's date precedes the Durán's observations by several decades and is believed to be more recent to the Aztec surrender to the Spanish. Both are shown to emphasize the fact that the beginning of the Native new year became non-uniform as a result of an absence of the unifying force of Tenochtitlan after the Mexica defeat.

Veintenas of the xiuhpōhualli

	Glyph	Name	Gregorian range		Presiding deities
			Durán	Sahagún
1		ātl cāhualo (“the water ceases”) cuahuitl ēhua (“the trees rise”)	March 01– March 20	February 02– February 21	Water gods
2		tlācaxīpēhualiztli (“flaying of men”)	March 21– April 09	February 22– March 13	Xipe Totec
3		tōzōztōntli (“lesser vigil”)	April 10– April 29	March 14– April 02	Tlaloc
4		huēyi tōzōztli (“greater vigil”)	April 30– May 19	April 03– April 22	Cinteotl
5		toxcatl (“dryness”)	May 20– June 08	April 23– May 12	Tezcatlipoca
6		etzalcualiztli (“eating of cooked maize and beans”)	June 09– June 28	May 13– June 01	Tlaloque
7		tēcuilhuitōntli (“lesser feast day”)	June 29– July 18	June 02– June 21	Huixtocihuatl
8		huēyi tēcuilhuitōntli (“greater feast day”)	July 19– August 07	June 22– July 11	Xilonen
9		tlaxōchimaco (“giving of flowers”) miccāilhuitōntli (“lesser feast day of the dead”)	August 08– August 27	July 12– July 31	Huitzilopochtli
10		xocotl huetzi (“the xocotl falls”) huēyi miccāilhuitl (“greater feast day of the dead”)	August 28– September 16	August 01– August 20	Xiuhtecuhtli
11		ochpaniztli (“sweeping”)	September 17– October 06	August 21– September 09	Teteo Innan
12		teōtlehco (“the gods arrive”)	October 07– October 26	September 10– September 29	All the gods
13		tepēilhuitl (“feast day of mountains”)	October 27– November 15	September 30– October 19	Mountains
14		quechōlli (“roseate spoonbill”)	November 16– December 05	October 20– November 8	Mixcoatl
15		panquetzaliztli (“raising of banners”)	December 06– December 25	November 09– November 28	Huitzilopochtli
16		ātemoztli (“descent of water”)	December 26– January 14	November 29– December 18	Rain gods
17		tititl (“tightening,” “contraction”)	January 15– February 03	December 19– January 07	Tonan
18		izcalli (“offshoot,” “bud”)	February 04– February 23	January 08– January 27	Xiuhtecuhtli
–		Unassigned days, not a veintena; often called nēmontēmi (“they fill up in vain”)	February 24– February 28	January 28– February 01	None

The five days inserted at the end of a year are days of reflection and contemplation still observed today.

Aztec years were named for the last day of their fourth month according to the 260-day calendar, the tonalpohualli.

Reconstruction of the calendar

For many centuries, scholars have tried to reconstruct the Aztec calendar. A correlation that is accepted in some circles was proposed by professor Rafael Tena (INAH), based on the studies of Sahagún, Durán and Alfonso Caso (UNAM). His correlation argues that the mexica year started on February 13th using the old Julian calendar or February 23rd of the current Gregorian calendar.

See also

• Aztec calendar
• Tianquiztli

References

• Miller, Mary; Karl Taube (1993). The Gods and Symbols of Ancient Mexico and the Maya. London: Thames and Hudson. ISBN 0-500-05068-6.