Caso (academic)
What it is
Alfonso Caso's correlation, the standard academic reconstruction. Anchored to two documented dates from the Conquest.
Why it does not fit the others' formula
Anchor at Julian Day 2,276,185, position 241, offset 0, day starting at midnight. From there: position = (241 + days elapsed) mod 260, and the numeral and the sign fall out of that.
How it is computed
Being a reconstruction, it does not propose a system of directions. None is invented for it here: where the source is silent, the field stays empty.
The algorithm
The full algorithm for this count lives as a file of its own, kept outside the code and sealed, so that it outlives the app and so that whoever inherits it knows what to implement.
What is published here is its data sheet — the anchor, the offset, when the day starts and when the year opens — and its control dates, which is what lets anyone check whether a calculation is right.
How to cite this page
Alma Mexica, «Caso (academic)», The five counts. Last revised 2026-09-17. https://almamexica.org/en/counts/caso/