Why Is Halloween Always October 31?

Quick answer: Halloween is October 31 because it is the eve of All Saints’ Day on November 1 in Western Christian calendars.

Where its name comes from

Halloween is a shortened form of All Hallows’ Eve, the evening before All Hallows’ Day.

Earlier seasonal traditions

Samhain was a Gaelic seasonal festival associated with the transition toward winter, though modern Halloween combines influences from different eras.

Modern customs

Costumes, decorations, trick-or-treating and parties developed through changing community traditions, especially in North America.

Date versus events

The holiday stays October 31 even when a city schedules an event or trick-or-treat period on a different day.

Quick answer

For planning purposes, always look for October 31 on the calendar and verify local event schedules separately.