Oh wait, Halloween is Catholic?
The word comes from "All Hallows Eve" — the vigil of All Saints Day. Together, October 31, November 1, and November 2 form Allhallowtide (also called Hallowtide), a sacred three-day observance centered on the souls of the departed and our call to holiness.
10/31 Parade of Saints
11/2 All Souls (novena)
October 31 — All Hallows Eve: The vigil of the great feast of All Saints. There's no reason for contemporary Catholics to shed the secular trappings of a modern Halloween — though certainly the more occult aspects should be shunned. Rather, Catholics simply remember its original purpose: to honor our dead — those who are surely in heaven, and those who are on their way, with prayers, offerings, and Masses. [Parade of Saints]
November 1 — All Saints Day (Holy Day of Obligation): Mass is required. Honor every soul in heaven — the canonized, the unknown, and perhaps your own beloved ancestors already at rest with God.
November 2 — All Souls Day: Offer Mass, the Rosary, and prayers for the souls in purgatory. Visit a cemetery. In some traditional Catholic homes, when night falls on November 1st, families darkened the room, lit a candle blessed at Candlemas, and prayed the Rosary for the repose of the souls of the dead — a beautiful practice any family can revive. [All Souls]