All Saints' Day, observed on November 1, honors all Christian saints — both known and unknown. It is closely linked with All Souls' Day (November 2), when the deceased are remembered.
Pope Gregory III dedicated a chapel in St. Peter's Basilica to All Saints in the 8th century, and Pope Gregory IV extended the feast to the whole church in 837. The date superseded the Celtic festival of Samhain in northern Europe.
Visiting cemeteries to leave flowers (especially chrysanthemums in France, Belgium, Italy, Portugal) and candles. Cemeteries glow with thousands of candles on the evening of November 1. In Poland (Wszystkich Świętych), nearly the entire country visits family graves.
All Souls bread (pan de muerto in Mexico). Sweets shaped like bones, skulls, or skeletons. Chestnuts and seasonal autumn foods.
Public holiday across most Catholic-majority European and Latin American countries. Cemeteries become candle-lit attractions in Poland, Lithuania, Romania. Most businesses close.