The term Halloween, and its older spelling Hallowe'en, is shortened from All-hallow-even, as it is the evening before "All Hallows' Day"[2] (also known as "All Saints' Day"). In Ireland, the name was All Hallows' Eve (often shortened to Hallow Eve), and though seldom used today, it is still a well-accepted label. The holiday was a day of religious festivities in various northern European Pagan traditions, until Pope Gregory III moved the old Christian feast of All Saints Day to November 1 to give Halloween a Christian interpretation . Halloween is also called Pooky Night in some parts of Ireland, presumably named after the púca, a mischievous spirit.
Halloween is often associated with the occult. Many European cultural traditions hold that Halloween is one of the liminal times of the year when the spiritual world can make contact with the physical world and when magic is most potent (e.g. Catalan mythology about witches, Irish tales of the Sídhe).