Alma Mexica
The Mexica calendar, with its sources and nothing invented
What this is
A project about Mexica culture and the Mexica calendar: the 260-day count and the solar year, as the sixteenth-century sources describe them and scholarship studies them.
It is two apps and this site, and one rule joins them: where each thing comes from is stated. When the sources contradict each other, the contradiction is published instead of choosing in silence.
The rule of the house
Everything on this site is in the Alma Mexica app, free. The rule runs one way and has no exceptions: nothing published here is charged for there.
Mexica Sign is a different thing: a daily-reading app, with ads in its free version. It provides the reading of the day, not the calendar — the calendar is free in both apps and on this site, without exception.
The five counts, the full bibliography and the record of contradictions are free everywhere, always. Rigour behind a paywall is advertising.
What is not done here
Nothing the sources do not say is invented. Where they are silent the gap is declared, and where they disagree both readings are shown with their folio.
The documented is not mixed with the living tradition. Both have worth and they are not the same; each text says which it is.
No arbitration between the five counts. Two calculators give different days because they start from different anchors, and choosing one for you would hide the problem.
Questions that reach this page
What is Alma Mexica?
A project about Mexica culture and the Mexica calendar — two apps and this site — publishing what the sixteenth-century sources say about each day, with the source in view. Not only the calendar: also the veintenas and their feasts, the sounding instruments, the herbal, the codices and daily life in Tenochtitlan. The calendar is free everywhere; nothing is charged for the information, only for the functionality.
Which of the two apps do I need?
Alma Mexica if you want the tonalamatl read in full: your sign described whole, the tonalpohualli, the trecenas and the veintenas, the use of calendar anchors, the sounding instruments and daily life in Tenochtitlan — all of it checked against reliable sources: codices from before and after the conquest, first-hand historical compilations and formal academic scholarship. Mexica Sign if you want your day read every morning, an integral reading grounded in the sources and in adaptive algorithms using advanced physico-mathematical models. They are independent and each works on its own.