Trecena (13-day period) Ollin
The thirteen day period (trecena) that starts with day 1-Ollin (Movement) is ruled by Tlazolteotl. This trecena is governed by the goddess of cotton and weaving, of sexuality and childbirth, she who is the eater of sins: it is the sign of the Scavenger, who feeds not on power but on the ills that darken the heart. The rainbow serpent, symbol of pleasure and folly, levitates amidst a shroud of smoke and shadow: these are 13 days of stolen secrets and odd twists of fate. The earth itself shakes: the ills created by shock can sometimes only be cured by greater shock. These are good days for self-purification; bad days for self-gratification.