The evening of Oct. 31, which precedes the church's celebration of All Saints' Day on Nov. 1. The BOS provides a form for a service on All Hallows' Eve. This service begins with the Prayer for Light, and it includes two or more readings from scripture. The options for the readings include the Witch of Endor (1 Sm 28:3-25), the Vision of Eliphaz the Temanite (Jb 4:12-21), the Valley of Dry Bones (Ez37;1-14), and the War in Heaven (Rv 12:[1-6]7-12). The readings are followed by a psalm, canticle, or hymn, and a prayer. The BOS notes that "suitable festivities and entertainments" may precede or follow the service, and there may be a visit to a cemetery or burial place.
The popular name for this festival is Halloween. It was the eve of Samhain, a pagan Celtic celebration of the beginning of winter and the first day of the new year. This time of the ingathering of the harvest and the approach of winter apparently provided a reminder of human mortality. It was a time when the souls of the dead were said to return to their homes. Bonfires were set on hilltops to frighten away evil spirits. Samhain was a popular festival at the time when the British Isles were converted to Christianity. The church "adopted" this time of celebration for Christian use by observing All Saints' Day on Nov. 1, and All Hallows' Eve on the evening of Oct. 31.