Halloween falls on October 31 every year; families in Europe and America typically start preparing costumes and candy in the evening, children go out for trick-or-treat after dark, and adults attend parties or decorate their porches
Its predecessor is the ancient Celtic festival of Samhain, when people believed the boundary between summer and autumn blurred, so they lit bonfires and wore masks; later, as it stood adjacent to the Catholic All Saints' Day on November 1, it gradually evolved into today's Halloween