1 Ozomahtli

Trecena 11 opens on 1 Ozomahtli, the monkey, under the patronage of Patecatl, lord of medicines, husband of Mayahuel and the deity credited in the myth cycle with discovering the roots and herbs, among them peyote in some tellings, used to ferment pulque and to treat illness. The monkey week is the pleasantest in the whole count by the readers' own judgment: its children read as friendly, gifted in song, dance and craft, welcome in any company they entered, though the tonalpouhque warned that such gifts scatter without discipline, a caution attached to nearly every favourable augury in the tonalpohualli and one that kept even the count's gentlest weeks from reading as unconditional blessings.

Patecatl's patronage of medicine and of pulque's more careful, healing use sits in contrast to Mayahuel's own trecena, the eighth, which reads as reversal and warns against pulque's dangers, the two consorts governing weeks with almost opposite auguries despite their shared connection to the same plant and its uses. A week favourable for the arts and for friendship by the sources' plain statement, this trecena's reputation made it, alongside Trecena 4's flower week, one of the two the tonalpouhque most associated with artistic gift among the whole twenty.

Trecena 11 runs from 1 Ozomahtli through 13 Calli, house, its span carrying monkey, grass, reed, jaguar, eagle, vulture, movement, flint, rain, flower and crocodile before closing on the sign that opens Trecena 15 next in the round. Calli, house, is itself one of the four year bearer signs, so this trecena closes on a day sign capable of naming an entire solar year in the 365 day xiuhpohualli, a significance layered atop its ordinary role here as the thirteenth and final day of the monkey week. Past the count's midpoint, this trecena sits within the stretch the tonalpouhque generally treated as easing after the harder run of trecenas six through ten, and its own favourable reading for arts and friendship continues that gentler run into the count's second half.

The patron bird system the Codex Borbonicus assigns to each of the thirteen numbers would have layered its own reading atop each of these thirteen days, a register distinct from both the trecena's overall patron Patecatl and the individual day signs' own characters, giving a diviner three separate sources of information to weigh for any single date falling within this favourable week. The friendly, gathering character the readers found in this trecena's children carries into how the tonalpouhque advised families to raise a monkey week child, encouraging the song and craft the sign favoured while watching for the scattering the readers warned against, since a gift given no direction was, in Nahua thought, as much a waste as a talent never discovered at all.