Tepeilhuitl is the name of the thirteenth month of the

Aztec calendar The Aztec or Mexica calendar is the calendar, calendrical system used by the Aztecs as well as other Pre-Columbian era, Pre-Columbian indigenous peoples of Mexico, peoples of central Mexico. It is one of the Mesoamerican calendars, sharing the bas ...

. It is also a festival in the

Aztec religion The Aztec religion is a polytheistic and monistic pantheism in which the Nahua concept of '' teotl'' was construed as the supreme god Ometeotl, as well as a diverse pantheon of lesser gods and manifestations of nature. The popular religion te ...

dedicated to Popocatepetl,

Iztaccihuatl Iztaccíhuatl or Ixtaccíhuatl (both forms also spelled without the accent) ( or, as spelled with the x, ) is a dormant volcanic mountain in Mexico located on the border between the State of Mexico and Puebla within Izta-Popo Zoquiapan National ...

and Tlaloc. It is called the festival or feast of the Mountains.

References

{{reflist Aztec calendars Aztec mythology and religion