Dia de los Muertos, 1 November

Dia de los Muertos runs two days from the first of November, the date this rule records, overlapping deliberately with the Catholic calendar's All Saints and All Souls. The popular account treats the observance as a direct, unbroken continuation of pre Columbian Aztec festivals for the dead pushed onto the nearest Catholic date by colonial era missionaries, and elements of that account are real, Mesoamerican traditions of ancestor veneration long predate the conquest. But the scholarship on the observance's actual formation is more cautious than the popular story, describing a fusion built up over centuries of colonial and postcolonial history rather than a straight line from a specific Aztec festival to the modern date, with much of the imagery now most associated with the day, including the elegant skeletal calavera figures, dating from considerably later, popularized by the nineteenth century printmaker Jose Guadalupe Posada.

The observance as practiced today centers on the ofrenda, a home altar built for the returning dead with photographs, marigolds, favorite foods and personal belongings of the deceased, alongside cemetery visits to clean and decorate graves. It remains most strongly associated with central and southern Mexico, particularly Indigenous communities in states such as Michoacan and Oaxaca, and has spread through the Mexican diaspora into a much wider public observance across North America over the past several decades, a modern expansion layered atop the older colonial fusion the date itself already represents.