Original sentence: The term Halloween, originally spelled Hallowe’en, is shortened from All Hallows’ Even (both even and eve are abbreviations of evening, but Halloween gets its n from even) as it is the eve of "All Hallows’ Day", which is now also known as All Saints’ Day
Edited sentence: The term Halloween, originally spelled Hallowe’en, is shortened from All Hallows’ Eve (both even and eve are abbreviations of evening, but Halloween gets its n from even) as it is the eve of "All Hallows’ Day", which is now also known as All Saints’ Day