The 260-day count
The Maya and Mexican cycle that joined thirteen numbers to twenty named days, so each pairing came round every 260 days. Most almanacs in the Dresden Codex are built on it.
Offerings for the Rain God (Dresden Codex, Pages 33 and 35)
Dresden Codex, pages 33 and 35: almanacs of the god B, with offerings, fishing and the serpent in the water (Yucatán, before the Spanish conquest) · painted in Yucatán, probably in the century before the Spanish conquest
X Akbal 9 · VI Eb 9 · II Imix 9 · XI Oc 2 · XIII Eb 4 · IV Cib 9 · XIII Chicchan 4 · IV Muluc 19
Ten Akbal, then nine days · six Eb, nine days · two Imix, nine days · eleven Oc, two days · thirteen Eb, four days · four Cib, nine days · thirteen Chicchan, four days · four Muluc, nineteen days
I · Caban · Muluc · Imix · Ben · Chicchan · 11 · XII
One, under the days Caban, Muluc, Imix, Ben and Chicchan · eleven days · twelve