1 Tecpatl

Trecena 10 opens on 1 Tecpatl, flint, under the patronage of Mictlantecuhtli, lord of the dead, with Tonatiuh the sun standing beside him in the codices, a pairing of the underworld and the sky's brightest body that marks the count's exact halfway trecena, the tenth of twenty. Sahagun ties the flint week to Huitzilopochtli, the Mexica's patron war god, and gives it a strong augury of courage and success in war and prosperity for those equal to its demands, a hard, bright week the readers judged favourable chiefly to the resolute, since flint itself, the sacrificial blade's own material, read as a sign rewarding those able to meet its severity rather than shrink from it.

Tecpatl is also one of the four year bearer signs, so this trecena's opening day could, in the separate 365 day solar count, name an entire fifty two year span of years bearing its number, giving the flint week additional significance beyond its own thirteen days whenever a year happened to fall on it. The pairing of the death lord with the sun in this trecena's patronage echoes the wider Mexica association of Huitzilopochtli himself with the sun's daily battle against darkness, fought and won anew each morning with the nourishment of sacrifice, a theology this trecena's hard, war favouring augury reflects directly.

Trecena 10 runs from 1 Tecpatl through 13 Itzcuintli, dog, its span carrying flint, rain, flower, crocodile, wind, house, lizard, serpent, death, deer and rabbit before closing on the sign that opens Trecena 14 next in the round. As the exact midpoint of the twenty trecena sequence, this week divides the tonalpohualli into two equal halves, and the tonalpouhque's tonalamatl tables mark it as a natural pivot in any full reading of the calendar's year, the point at which a reader working through the whole 260 day count from Cipactli onward reached the halfway mark.

The dog sign that closes this trecena carries its own separate reading as the guide of the dead across the river to Mictlan in the wider mythology, a fitting closing note for a week already patronised jointly by the death lord and the sun, so that this trecena's thirteen days move thematically from the sacrificial flint of its opening through war and prosperity to the dog's psychopomp role at its close. No other trecena in the count carries quite this concentration of death and warfare imagery across its full span, a pattern the tonalpouhque would have read as making Trecena 10 among the most demanding weeks to navigate successfully.