Acatl (MH545r)

This is a sign in the tonalpohualli, the 260-day divinatory calendar. Typically, a name with a day sign such as this would have a number with it. But by 1560, the timing of this manuscript, sometimes just the day sign was used and the number was dropping away. Alternatively, sometimes just the number was used (e.g., Macuilli), and the day sign was omitted. Whether this was happening to disguise the continued use of the tonalpohualli in naming children, which might have displeased the colonizing clergy, or whether it was a gradual, inadvertent change, is difficult to know.