Day of the Dead is perhaps Mexico's most famous celebration. So what is it and how is it celebrated? Day of the Dead, or “Día de Muertos” in Spanish, is a festival to commemorate the dead and a public holiday in Mexico. Day of the Dead runs from October 31st to All Souls Day, on November 2nd. Rituals honouring the dead date back several thousand years, all the way to the Aztecs. However, the current traditions mostly took shape during the 20th century.