History of Halloween

Chase's Calendar of Events 2008 says this about Hallowe'en or All Hallow's Eve, October 31:

An ancient celebration combining Druid autumn festival and Christian customs. Hallowe'en (All Hallow's Eve) is the beginning of Hallowtide, a season that embraces the Feast of All Saints (Nov. 1) and the Feast of All Souls (Nov. 2). The observance, dating from the sixth or seventh century, has long been associated with thoughts of the dead, spirits, witches, ghosts and devils. In fact, the ancient Celtic Feast of Samhain [pronounced Sown], the festival that marked the beginning of winter and of the New Year, was observed Nov. 1.