1 Quiahuitl

Trecena 7 opens on 1 Quiahuitl, rain, under the patronage of Tlaloc, giver of rain and among the oldest deities attested in central Mexico, his cult traceable in the archaeological record to Teotihuacan long before the Mexica adopted him as one of the two gods honoured at the templo mayor's twin shrines. Sahagun's fourth book calls this the sorcerers' week, recording that the nanahualtin, the shape changers of Nahua belief, were said to be born within it, and its days read as dangerous, apt for illness and for uncanny meetings that a traveller or a household head was warned to guard against.

An unfavourable week overall, its power, the readers held, could be turned by offering but never simply ignored, a formula the sources apply to several of the count's harder trecenas but state with particular force here, in keeping with Tlaloc's own double character as a god equally capable of nourishing rain and destroying storm. The rain god's patronage of a week associated with shape changing sorcery draws on the same logic that linked him to mountain caves and to the tlaloque, his company of lesser rain spirits, since caves and mountains were the places Nahua cosmology treated as thresholds where ordinary reality gave way to more dangerous forces.

Trecena 7 runs from 1 Quiahuitl through 13 Ozomahtli, monkey, carrying the sequence through rain, flower, crocodile, wind, house, lizard, serpent, death, deer, rabbit and water before closing on the sign that opens Trecena 11 next in the round. Sitting past the count's first third, this trecena's reputation as the sorcerers' week made it, per the general pattern the tonalpouhque's craft followed, one that families actively sought to avoid for a child's birth where the timing of conception allowed any choice at all, though Sahagun's account is clear that birth dates were rarely chosen and the reading instead shaped how a family raised a child born under a difficult sign, through additional penance, a shifted naming day, or heightened attention to the remedies a priest recommended.

The trecena's span crosses none of the four year bearer signs directly as an opener or closer, Quiahuitl and Ozomahtli both standing outside that select group of four, which the tonalpouhque would have noted as one register in which this particular week carried no additional solar year significance beyond its own thirteen days within the 260 day tonalpohualli, its difficulty confined to the divinatory count alone.