The Aztec Calendar, also widely recognized as the Sun Stone, stands as one of the most iconic symbols of Mexico, rivaling even the national flag in its cultural significance. This monumental artifact offers a profound glimpse into the sophisticated worldview, religious beliefs, and advanced astronomical knowledge of the Aztec civilization.
A Monumental Masterpiece
The original Aztec Calendar is a massive, circular stone slab, meticulously carved from basalt in the mid-15th century. Its sheer size and intricate carvings are awe-inspiring. While numerous replicas and representations of the stone exist throughout Mexico and beyond, the original remains a testament to the artistic and engineering prowess of the Aztec people.
Historically, the Aztecs referred to this imposing monolith as the Cuauhxicalli (Eagle Bowl), a name that hints at its ritualistic function. However, its more common designation, the Aztec Calendar or Sun Stone, reflects its primary purpose as a complex system for tracking time and honoring the sun god, Tonatiuh. The stone was commissioned during the reign of the sixth Aztec monarch, in 1479, and dedicated to this principal deity. Its significance is both mythological and astronomical, embodying the Aztec understanding of the cosmos and their place within it.
The sheer scale of the stone is remarkable. It weighs approximately 25 tons, measures just under 12 feet in diameter, and boasts a thickness of 3 feet. These dimensions underscore the immense effort and resources required for its creation.
Rediscovery and Preservation
For centuries, the Aztec Calendar lay hidden from view. On December 17th, 1760, it was unearthed in the Zócalo, the main square of Mexico City, during a period when Don Joaquín de Monserrat, Marquis of Cruillas, served as the viceroy of New Spain. Following its rediscovery, the stone was embedded in the wall of the Western tower of the Metropolitan Cathedral, where it remained for over a century.
In 1885, recognizing its immense historical and cultural value, General Porfirio Díaz, the then President of the Republic, ordered the stone’s transfer to the National Museum of Archaeology and History. Today, it resides there as one of the museum’s most prized exhibits, attracting visitors from around the world who come to marvel at its intricate carvings and learn about the fascinating civilization that created it.
Two Intertwined Calendrical Systems
The Aztec Calendar wasn’t a single, unified system for tracking time. Instead, it comprised two distinct but interconnected calendars: the tonalpohualli (the "counting of days") and the xiuhpohualli (the "counting of years"). These two calendars worked in tandem to create a comprehensive framework for understanding the passage of time, predicting auspicious dates, and organizing religious ceremonies.
The Tonalpohualli: A Sacred Almanac
The tonalpohualli was a 260-day cycle, believed to have originated from ancient observations of the sun’s zenith passage near the Mayan city of Copán. This sacred calendar was divided into 20 periods, each consisting of 13 days, known as trecenas. Each period was assigned a specific name, represented by a hieroglyphic sign, and each trecena was associated with a number from 1 to 13. Furthermore, each trecena was believed to be presided over by a specific god or deity.
The Aztecs recorded the tonalpohualli in tonalamatls, screenfold books made from bark paper. These books served as almanacs, guiding priests in determining auspicious days for various activities, such as planting crops, constructing buildings, and engaging in warfare. The tonalpohualli was, therefore, a deeply religious calendar, used to understand the divine influences shaping daily life.
The Xiuhpohualli: The Solar Year
The xiuhpohualli was a 365-day solar calendar, reflecting the Aztec understanding of the Earth’s orbit around the sun. This calendar served as the agricultural and ceremonial calendar of the Aztec state. It was divided into 18 periods, each consisting of 20 days, called veintenas. This division accounted for 360 days, leaving five days unrepresented.
These remaining five days were known as the nemontemi, which translates to "empty days." They were considered a transitional period between the old and the new year, and were regarded as ominous days marked by the cessation of normal activities and general abstinence. This was a time of festivals, where people adorned themselves in their finest attire, participated in singing and dancing, and witnessed priestly sacrifices. While human sacrifices were not uncommon, animals and fruits were also offered to the gods.
The xiuhpohualli served as the foundation for the civil calendar, guiding the Mexicas (Aztecs) in determining the myriad ceremonies and rituals linked to agricultural cycles. The precise correlation of dates in the Gregorian calendar remains uncertain, although many scholars align the beginning of the Aztec year with early February.
The Mesoamerican Century: Binding Up of the Years
Every 52 years, the tonalpohualli and the xiuhpohualli calendars would align, marking what was known as a Mesoamerican "century." This significant event was commemorated with a grand festival called xiuhmolpilli, meaning "Binding Up of the Years" or the New Fire Ceremony.
This festival lasted for 12 days and involved fasting as a symbol of penitence. At the commencement of the festival, all the lights in the city were extinguished, symbolizing a period of darkness and renewal. On the midnight of the 12th day, a prisoner was taken to the priest. The priest would observe the night sky, waiting for the star of fire to reach its zenith. Upon reaching this point, the priest would remove the heart of the prisoner and replace it with a piece of wood, which was then placed on a piece of turquoise. This served as the kindling for the new fire that would once again illuminate the city.
The tonalpohualli (count of days) was the sacred almanac of the Mexicas. This ritual calendar was registered in the tonalamatl (book of days), a screen-fold bark paper or deerskin codex from which a priest (called tonalpouque) cast horoscopes and predicated favorable and unfavorable days of the cycle. The almanac year comprised of 260 days, each of which was assigned a date by intermeshing one of 20 day-signs, represented graphically with a glyph, and a number from 1 to13, represented by dots so that no two days in the cycle could be confused.
The almanac year was thus made up of 20 13-day weeks, with the first week beginning on 1-Crocodile and ending on 13-Reed, the second week running from 1-Ocelot to 13-Deaths’ Head and so on. A god or goddess was believed to preside over each day-sign.
Decoding the Sun Stone
The Aztec Calendar is far more than just a calendar; it’s a complex representation of the Aztec worldview, cosmology, and religious beliefs. The intricate carvings that adorn its surface are laden with symbolism, offering insights into the Aztec understanding of the universe and their place within it. Understanding the symbolism is crucial to appreciating the depth and sophistication of this remarkable artifact.
The central figure on the stone is often identified as Tonatiuh, the sun god, although some scholars argue it represents a composite deity. Surrounding this central figure are various rings and symbols that represent different aspects of the Aztec calendar system, including the 20 day signs, the 52-year cycle, and other cosmological elements.
Studying the Aztec Calendar provides invaluable insights into the intellectual achievements and cultural practices of the Aztec civilization. It underscores their sophisticated understanding of astronomy, mathematics, and art, and offers a glimpse into their complex religious beliefs and rituals.