Calendar name

In Mesoamerica, every single person had a calendar name determined by their day of birth in the sacred calendar. Said name was composed of a numeral ranging from 1 to 13, and one of the 20 day-signs, creating a combination of 260 possible calendar names. Although each region and culture had their own versions of the 260-day calendar, they were all essentially the same and equivalent.

This was the first name a child would attain upon birth and was said to somehow determine said person's fate. The person would later be given a name based on their physical or personality traits, personal achievements, a fate foretold by a diviner, etc.

Most characters in Codex Black only use their personal names, but they all have a calendar name based on their birthday. Other characters, like the Huijatao Yalaana (11-Death), use their calendar name instead.

Nahua - Tonalpohualli
The Tonalpohualli is the Nahua sacred 260 day calendar. The 20 day-signs of this calendar are:
 * 1) Cipactli - Crocodile
 * 2) Ehecatl - Wind
 * 3) Calli - House
 * 4) Cuetzpalin - Lizard
 * 5) Coatl - Snake
 * 6) Miquiztli - Death
 * 7) Mazatl - Deer
 * 8) Tochtli - Rabbit
 * 9) Atl - Water
 * 10) Itzcuintli - Dog
 * 11) Ozomahtli - Monkey
 * 12) Malinalli - Grass
 * 13) Acatl - Reed
 * 14) Ocelotl - Jaguar
 * 15) Cuauhtli - Eagle
 * 16) Cozcacuauhtli - Vulture
 * 17) Ollin - Movement
 * 18) Tecpatl - Flint knife
 * 19) Quiyahuitl - Rain
 * 20) Xochitl - Flower

Zapotec - Píye
The Zapotec had their own sacred calendar called Píye, which some scholars argue to have been the oldest 260-day calendar in all of Mesoamerica. Some of its day-signs are different to the well known Tonalpohualli or the Mixtec calendar, but they're essentially the same.

Certain characters of Zapotec origin, like Donaji or Béelia, use the Zapotec Piye for their calendar names instead of the Nahua version; that's the reason why Donaji's name is 12-Lord instead of 12-Flower and Béelia's is 1-Night instead of 1-House.