The tonalpohualli
The count of days — 260
What it covers
The 260-day count: twenty signs by thirteen numerals, how it is read and what it was used for.
The full entry is in Spanish, and here is why
What you have read above is this project's own summary of the tonalpohualli. The full entry — the part that rests on the sixteenth-century sources — has not been translated, and that is a decision rather than an omission.
We chose not to touch the primary text. Those sections quote Sahagún, Durán and the codices in their own words, often in sixteenth-century Castilian. A quotation carried across stops being a quotation: it loses the register, the ambiguity and the exact wording someone might want to check against a facsimile.
In Spanish the entry carries:
- Cómo funciona
- Nunca se detiene
- Lo que lo acompaña
- ¿De dónde salen los 260?
- De dónde sale la patrona
- Las dos primeras, de otro códice
- Las energías también tenían su día
- Preguntas que llegan a esta página
Read the full entry in the original Spanish → Nahuatl names and terms are identical in both versions.
How to cite this page
Alma Mexica, «The tonalpohualli», The sky and the cycles. Revised 2026-09-17. https://almamexica.org/en/cycle/tonalpohualli/
Questions that reach this page
What is the tonalpohualli?
The 260-day count of the Aztec calendar: twenty day-signs combined with thirteen numbers. Each day carries a number and a sign — 1-Cipactli, 2-Ehécatl — and the pair does not repeat until all 260 have gone by. It runs alongside the 365-day solar year, and crossing the two gives the 52-year round.
Why does the Aztec calendar have 260 days?
Because twenty signs times thirteen numbers give 260 combinations, and thirteen and twenty share no divisors: every pairing has to be used before the cycle returns to its start. The sources do not say why those two numbers were chosen, and what circulates about gestation or about Venus are modern hypotheses, not something Sahagún or the codices state.
Is the tonalpohualli the same as the Aztec calendar?
It is one of its two counts. The other is the xiuhpohualli, the solar year of eighteen twenty-day months plus five days. Calling only the tonalpohualli «the Aztec calendar» is the commonest confusion in the subject: the two run at the same time and count different things.