All Hallows’ Eve is observed every year on October 31, the evening before All Saints’ Day on November 1.

Date and meaning

  • All Hallows’ Eve is another name for what most people now call Halloween.
  • It falls annually on October 31 as the vigil (eve) before the Christian feast of All Saints’ Day, also called All Hallows’ Day.

Quick context

  • The word hallow means “holy,” so “All Hallows’ Eve” literally means the evening before the day of all the holy ones (saints).
  • In many Western countries, the religious vigil and the modern, more secular Halloween celebration now happen on the same night: October 31.

TL;DR: When is All Hallows’ Eve? It’s on October 31 every year, right before All Saints’ Day on November 1.

Information gathered from public forums or data available on the internet and portrayed here.