Calendar, Cosmos, and Modern Misreadings

The stone is popularly called the Aztec calendar, and it does encode calendrical structure, the twenty day-signs and the cosmology of the five Suns, but it was almost certainly not a working calendar or clock. It is a cosmological and probably political monument, likely a ceremonial surface or a horizontally mounted altar carved under the ruler Axayacatl or a successor in the late fifteenth century. Its outermost ring is formed by two Xiuhcoatl, turquoise or fire serpents associated with the sun's daily journey, whose flame-adorned bodies curve around the entire disc with their tails meeting at the top beside a further date glyph read as 13 Reed; specialists differ on what that date marks, some connect it to the legendary beginning of the present Sun, others to the year the stone itself was carved, and the atlas records both readings rather than choosing between them.

Much popular material projects onto the stone precise prophecies and New Age meanings the Mexica did not record. The reliable account rests on the stone itself and on early colonial sources such as Sahagun's Florentine Codex. The Mexica are not a people of the past; their descendants are among the living Nahua of Mexico.