abstract:The Xiuhpohualli ) (literally, year/xihuitl-count/pohualli) was a 365-day calendar used by the Aztecs and other pre-Columbian Nahua peoples in central Mexico. It was composed of eighteen 20-day "months," called veintenas or metztli (the contemporary Nahuatl word for month) with a separate 5 day period at the end of the year called the nemontemi.