Trecena 15, Opening on Calli

Trecena 15 opens on 1 Calli, house, under the patronage of Itzpapalotl, the obsidian butterfly, a fearsome goddess associated with the Tzitzimime, the star demons Mexica belief held would descend and devour humanity should the sun fail to rise, most feared during the darkness of a solar eclipse, and remembered in some sources as patroness of the Chichimec peoples of the northern deserts. Sahagun's fourth book gives this week's children sickness and misfortune, an augury the readers softened only by moving naming days to better numbers within the week, one of the more directly unfavourable trecenas in the whole count and matched to a patron whose own character carries little of the gentler ambiguity found in some of the pantheon's more forgiving deities.

A week for staying within walls and discharging duties owed, by the readers' own description, its house sign opening fits this reading of caution and enclosure directly: Calli, shelter and the hearth, read here not as safety freely enjoyed but as a confinement made necessary by the week's difficulty, a family kept close to home rather than venturing out under a dangerous sky. Calli is also one of the four year bearer signs, giving this trecena's opening additional weight whenever a solar year happened to begin on it.