Halloween or Hallowe'en, also known as Allhalloween, All Hallows' Eve, or All Saints' Eve, is a celebration observed in many countries on 31 October, the eve of the Western Christian feast of All Hallows' Day.br Date: Saturday, 31 October, 2020 Trendingbr Significance: First day of Allhallowtidebr Observances: Church services, prayer, fasting, and vigilbr Observed by: Western Christians and many non-Christians around the worldbr Origin: Samhainbr Also called: Hallowe'en, Allhallowe'en, All Hallows' Eve, All Saints' Evebr The tradition originated with the ancient Celtic festival of Samhain, when people would light bonfires and wear costumes to ward off ghosts.