Acatl's patron in the day sign count is Tezcatlipoca, the smoking mirror, whose severe, testing character across his several manifestations sits somewhat uneasily beside the reed's hollow, talkative augury, though his patronage here is recorded plainly in the sources without further comment connecting the two. Its direction is east, and as one of the four year bearer signs Acatl specifically names the years of the eastern quarter across the fifty two year Calendar Round, the same span of years the sign's connection to Quetzalcoatl's calendar name made especially freighted with meaning in the colonial era retellings of the conquest period.
The mechanics of year bearing follow the same arithmetic for every one of the four signs: 365 days exceeds an even multiple of twenty by five, so each solar year's opening day sign advances five places from the year before, and since twenty divided by five yields four, only four signs spaced exactly that far apart, Calli, Tochtli, Acatl and Tecpatl, ever recur as year openers. An Acatl year, carrying both the reed sign's ordinary hollow augury and its extraordinary association with Quetzalcoatl's name, would have been read by the tonalpouhque as a year of particular consequence, whatever number among the thirteen possible it happened to carry.