Matlactli omome
12 in Nahuatl · purification
What it is
Matlactli omome is the Nahuatl for 12 and one of the thirteen numerals of the tonalpohualli. It goes with each of the twenty day-signs, so thirteen days in every 260-day round carry this numeral. Its Lord of the Day is Tlahuizcalpantecuhtli.
Why thirteen and not twenty
Because there are two counts running at once. The signs are twenty and the numerals thirteen, and they advance together: 1-Cipactli, 2-Ehécatl, 3-Calli… When the numeral reaches 13 it returns to 1 while the signs carry on. The pair takes 260 days to repeat, which is the lowest common multiple of 13 and 20.
Its Lord of the Day
It is ruled by Tlahuizcalpantecuhtli, which governs the days of number 12.
Its twenty days
In each turn of the two hundred and sixty days, the number 12 accompanies each of the twenty signs once: 12-Cipactli, 12-Ehecatl, and so on to 12-Xochitl. Twenty days per turn, and thirteen turns to close the count.
What is not here, and why
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.
Read the sourced commentary in Spanish → Nahuatl terms and day names are the same in both versions.
How to cite this page
Alma Mexica, «Matlactli omome», The thirteen numerals. Revised 2026-09-17. https://almamexica.org/en/numeral/12-matlactli-omome/
How it is written
The number 12 as the codices write it: 12 dots. The Mexica system is additive and uses dots only — the bar worth five is Maya practice, and does not appear in the count of days.