Halloween (also spelled Hallowe'en) is an annual holiday observed on October 31. It has roots in the Celtic festival of Samhain and the Christian holiday All Saints' Day, but is today largely a secular celebration.
Halloween activities include trick-or-treating, wearing costumes and attending costume parties, carving jack-o'-lanterns, ghost tours, bonfires, apple bobbing, visiting haunted attractions, pranks, telling scary stories, and watching horror films.
Source: http://en.wikipedia.org/wiki/Halloween
