High Quality Content by WIKIPEDIA articles! The tonalpohualli, a Nahuatl word meaning "count of days", is a 260-day sacred period (often termed a "year") in use in pre-Columbian Mesoamerica, especially among the Aztecs. This calendrical period is neither solar nor lunar, but rather consists of 20 trecena, or 13-day periods. Each trecena is dedicated to and under the auspices of a different deity.