Halloween, All Hallows' Eve

"Dómine, Deus noster, multíplica super nos grátiam tuam: et, quorum prævenimus gloriósa solemnia, tríbue subsequi in sancta professióne lætítiam."

"Pour forth abundantly upon us of thy mercy, O Lord our God, and grant us grace to follow in their joy in their holy testifying all thy blessed servants the Eve of whose glorious and solemn Commemoration we are keeping."

Information on Halloween and its connection to the Church's calendar.

All Hallows' Eve

Not many people know this but Halloween or All Hallows' Eve is a day when Catholics should meditate on the reality of Hell and how people who die in a state of mortal sin enter such a place.  Thus, the days of Hallowtide remind of us of Hell, Heaven, and Purgatory in that order.

Here is a pertinent link from Fisheaters which will explain the Catholic nature of Halloween.