Aztec calendar

The Aztec or Mexica calendar is the calendrical system used by the Aztecs as well as other Pre-Columbian peoples of central Mexico. It is one of the Mesoamerican calendars, sharing the basic structure of calendars from throughout ancient Mesoamerica.

Monolito de la Piedra del Sol.jpg

The Aztec sun stone, also called the calendar stone, is on display at the National Museum of Anthropology in Mexico City. The calendar consists of a 365-day calendar cycle called xiuhpōhualli (year count) and a 260-day ritual cycle called tōnalpōhualli (day count). These two cycles together form a 52-year "century", sometimes called the "calendar round". The xiuhpōhualli is considered to be the agricultural calendar, since it is based on the sun, and the tōnalpōhualli is considered to be the sacred calendar.


The tōnalpōhualli ("day count") consists of a cycle of 260 days, each day signified by a combination of a number from 1 to 13, and one of the twenty day signs. With each new day, both the number and day sign would be incremented: 1 Crocodile is followed by 2 Wind, 3 House, 4 Lizard, and so forth up to 13 Reed, after which the cycle of numbers would restart (though the twenty day signs had not yet been exhausted) resulting in 1 Jaguar, 2 Eagle, and so on, as the days immediately following 13 Reed. This cycle of number and day signs would continue similarly until the 20th week, which would start on 1 Rabbit, and end on 13 Flower. It would take a full 260 days (13×20) for the two cycles (of twenty day signs, and thirteen numbers) to realign and repeat the sequence back on 1 Crocodile.

Day signs

The set of day signs used in central Mexico is identical to that used by Mixtecs, and to a lesser degree similar to those of other Mesoamerican calendars. Each of the day signs also bears an association with one of the four cardinal directions.[1][2]

There is some variation in the way the day signs were drawn or carved. Those here were taken from the Codex Magliabechiano.

ImageNahuatl namePronunciationEnglish translationDirection
Crocodilian Monster
ImageNahuatl namePronunciationEnglish translationDirection
Olin (Aztec glyph from the Codex Magliabechiano).jpgŌlīn[ˈoːliːn̥]Movement
Flint Knife

Wind and Rain are represented by images of their associated gods, Ehēcatl and Tlāloc respectively.

Other marks on the stone showed the current world and also the worlds before this one. Each world was called a sun, and each sun had its own species of inhabitants. The Aztecs believed that they were in the Fifth Sun and like all of the suns before them they would also eventually perish due to their own imperfections. Every 52 years was marked out because they believed that 52 years was a life cycle and at the end of any given life cycle the gods could take away all that they have and destroy the world.


The 260 days of the sacred calendar were grouped into twenty periods of 13 days each. Scholars usually refer to these thirteen-day "weeks" as trecenas, using a Spanish term derived from trece "thirteen" (just as the Spanish term docena "dozen" is derived from doce "twelve"). The original Nahuatl term is not known.

Each trecena is named according to the calendar date of the first day of the 13 days in that trecena. In addition, each of the twenty trecenas in the 260-day cycle had its own tutelary deity:

1 CrocodileTonacatecuhtli1 MonkeyPatecatl
1 JaguarQuetzalcoatl1 LizardItztlacoliuhqui
1 DeerTepēyōllōtl1 QuakeTlazōlteōtl
1 FlowerHuēhuecoyōtl1 DogXīpe Totēc
1 ReedChalchiuhtlicue1 HouseĪtzpāpālōtl
1 DeathTōnatiuh1 VultureXolotl
1 RainTlāloc1 WaterChalchiuhtotolin
1 GrassMayahuel1 WindChantico
1 SnakeXiuhtecuhtli1 EagleXōchiquetzal
1 FlintMictlāntēcutli1 RabbitXiuhtecuhtli


In ancient times the year was composed of eighteen months, and thus it was observed by the native 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.

Xiuhpōhualli is the Aztec year (xihuitl) count (pōhualli). One year consists of 360 named days and 5 nameless (nēmontēmi). These 'extra' days are thought to be unlucky. The year was broken into 18 periods of twenty days each, sometimes compared to the Julian month. The Nahuatl word for moon is metztli but whatever name was used for these periods is unknown. Through Spanish usage, the 20-day period of the Aztec calendar has become commonly known as a veintena.

Each 20-day period started on Cipactli (Crocodile) for which a festival was held. The eighteen veintena are listed below. The dates are from early eyewitnesses; each wrote what they saw. Bernardino de Sahagún's date precedes the observations of Diego Durán by several decades and is believed to be more recent to the surrender. 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.

#Durán timeSahagún timeFiesta namesSymbolEnglish translation
1Mar 1 – Mar 20Feb 2 – Feb 21Atlcahualo, CuauhitlehuaMetzliAtlca.jpgCeasing of Water, Rising Trees
2Mar 21 – Apr 9Feb 22 – Mar 13TlacaxipehualiztliMetzliTlaca.jpgRites of Fertility; Xipe-Totec ("the flayed one")
3Apr 10 – Apr 29Mar 14 – Apr 2TozoztontliMetzliToz.jpgLesser Perforation
4Apr 30 – May 19Apr 3 – Apr 22Huey TozoztliMetzliToz2.jpgGreater Perforation
5May 20 – Jun 8Apr 23 – May 12TōxcatlMeztliToxcatl.jpgDryness
6Jun 9 – Jun 28May 13 – Jun 1EtzalcualiztliMeztliEtzal.jpgEating Maize and Beans
7Jun 29 – July 18Jun 2 – Jun 21TecuilhuitontliMeztliTecu.jpgLesser Feast for the Revered Ones
8July 19 – Aug 7Jun 22 – Jul 11Huey TecuilhuitlMeztliHTecu.jpgGreater Feast for the Revered Ones
9Aug 8 – Aug 27Jul 12 – Jul 31Tlaxochimaco, MiccailhuitontliMeztliMicc.jpgBestowal or Birth of Flowers, Feast to the Revered Deceased
10Aug 28 – Sep 16Aug 1 – Aug 20Xócotl huetzi, Huey MiccailhuitlMeztliMiccH.jpgFeast to the Greatly Revered Deceased
11Sept 17 – Oct 6Aug 21 – Sept 9OchpaniztliMeztliOch.jpgSweeping and Cleaning
12Oct 7 – Oct 26Sept 10 – Sept 29TeotlecoMeztliTeo.jpgReturn of the Gods
13Oct 27 – Nov 15Sept 30 – Oct 19TepeilhuitlMeztliTep.jpgFeast for the Mountains
14Nov 16 – Dec 5Oct 20 – Nov 8QuecholliMeztliQue.jpgPrecious Feather
15Dec 6 – Dec 25Nov 9 – Nov 28PānquetzaliztliMeztliPanq.jpgRaising the Banners
16Dec 26 – Jan 14Nov 29 – Dec 18AtemoztliMetzliAtem.jpgDescent of the Water
17Jan 15 – Feb 3Dec 19 – Jan 7TititlMeztliTitl.jpgStretching for Growth
18Feb 4 – Feb 23Jan 8 – Jan 27IzcalliMeztliIzcalli.jpgEncouragement for the Land & People
18uFeb 24 – Feb 28Jan 28 – Feb 1nēmontēmi (5 day period)MeztliNem.jpgEmpty days (no specific activities or holidays)


The ancient Mexicans counted their years by means of four signs combined with thirteen numbers, thus obtaining periods of 52 years,[3] which are commonly known as Xiuhmolpilli, a popular but incorrect generic name; the most correct Nahuatl word for this cycle is Xiuhnelpilli.[4] The table with the current years:

Tlalpilli TochtliTlalpilli AcatlTlalpilli TecpatlTlalpilli Calli
1 tochtli / 19741 acatl / 19871 tecpatl / 20001 calli / 2013
2 acatl / 19752 tecpatl / 19882 calli / 20012 tochtli / 2014
3 tecpatl / 19763 calli / 19893 tochtli / 20023 acatl / 2015
4 calli / 19774 tochtli / 19904 acatl / 20034 tecpatl / 2016
5 tochtli / 19785 acatl / 19915 tecpatl / 20045 calli / 2017
6 acatl / 19796 tecpatl / 19926 calli / 20056 tochtli / 2018
7 tecpatl / 19807 calli / 19937 tochtli / 20067 acatl / 2019
8 calli / 19818 tochtli / 19948 acatl / 20078 tecpatl / 2020
9 tochtli / 19829 acatl / 19959 tecpatl / 20089 calli / 2021
10 acatl / 198310 tecpatl / 199610 calli / 200910 tochtli / 2022
11 tecpatl / 198411 calli / 199711 tochtli / 201011 acatl / 2023
12 calli / 198512 tochtli / 199812 acatl / 201112 tecpatl / 2024
13 tochtli / 198613 acatl / 199913 tecpatl / 201213 calli / 2025

Reconstruction of the Solar calendar

For many centuries scholars had tried to reconstruct the Calendar. A widely accepted version was proposed by Professor Rafael Tena of the Instituto Nacional de Antropología e Historia,[5] based on the studies of Sahagún and Alfonso Caso of the National Autonomous University of Mexico. His correlation argues that the first day of the Mexica year was February 13 of the old Julian calendar or February 23 of the current Gregorian calendar. Using the same count, it has been the date of the birth of Huitzilopochtli, the end of the year and a cycle or "Tie of the Years", and the New Fire Ceremony, day-sign 1 Tecpatl of the year 2 Acatl,[6] corresponding to the date February 22. Another correlation by Ruben Ochoa uses pre-Columbian sources to reconstruct the calendar, using a method that fixes the year count to the vernal equinox and placing the first day of the year on the first day after the equinox.[7]

See also


  1. ^ Hill Boone, Elizabeth (2016). Ciclos de tiempo y significado en los libros mexicanos del destino [Cycles of time and meaning in the Mexican books of destiny]. Mexico City: Fondo de Cultura Económica. ISBN 9786071635020.
  2. ^ Beuchat, Henri (1918). Manual de arqueología americana [Manual of American Archeology]. Madrid: Daniel Jorro. pp. 349–352.
  3. ^ Tena, 2008: 103. There he shows us a table.
  4. ^ Tena, 2008:9.
  5. ^ The Mexica Calendar and the Chronography, Rafael Tena. INAH-CONACULTA. 2008
  6. ^ Crónica Mexicayotl, Fernando Alvarado Tezozomoc p 36
  7. ^ Azteca/Mexica Calendar Correlations: the Good, the Bad, and the Completely Useless, Itztli Ehecatl. 2015


External links

Media files used on this page

The Aztec day sign coatl (snake).
The Aztec day sign cipactli (crocodile).
(c) Grae Bear at en.wikipedia, CC BY 3.0
Quecholli is the name of the fourteenth month of the Aztec calendar. It is also a festival in the Aztec religion and the Principal deity is Mixcoatl. It is called the Precious Feather and hunting is done during this season. Edit this at Structured Data on Commons
The Aztec day sign calli (house).
The Aztec day sign quiahuitl (rain).
Grabado de la Fundación de México.svg
Author/Creator: Ludovicus Ferdinandus can have elements by Sodacan and Heralder, Licence: CC BY-SA 3.0
Depiction of the fundational myth of Mexico-Tenochtitlan.
The Aztec day sign acatl (reed).
The Aztec day sign cozcacuauhtli (vulture).
The Aztec day sign ocelotl (jaguar).
The Aztec day sign cuauhtli (eagle).
The Aztec day sign tecpatl (flint).
The Aztec day sign ehecatl (wind).
The Aztec day sign miquiztli (death).
The Aztec day sign atl (water).
The Aztec day sign malinalli (grass).
The Aztec day sign cuetzpalin (lizard).
The Aztec day sign mazatl (deer).
The Aztec day sign itzcuintli (dog).
The Aztec day sign tochtli (rabbit).
The Aztec day sign xochitl (flower).
Monolito de la Piedra del Sol.jpg
Author/Creator: El Comandante, Licence: CC BY-SA 3.0
Monolith of the Stone of the Sun, also named Aztec calendar stone (National Museum of Anthropology and History, Mexico City).
The Aztec day sign ozomatli (monkey).