<Tr> <Th> Date </Th> <Td> 31 October </Td> </Tr> <Tr> <Th> Related to </Th> <Td> Totensonntag, Blue Christmas, Thursday of the Dead, Samhain, Hop - tu - Naa, Calan Gaeaf, Allantide, Day of the Dead, Reformation Day, All Saints' Day, Mischief Night (cf . vigils) </Td> </Tr> <P> Halloween or Hallowe'en (a contraction of All Hallows' Evening), also known as Allhalloween, All Hallows' Eve, or All Saints' Eve, is a celebration observed in a number of countries on 31 October, the eve of the Western Christian feast of All Hallows' Day . It begins the three - day observance of Allhallowtide, the time in the liturgical year dedicated to remembering the dead, including saints (hallows), martyrs, and all the faithful departed . </P> <P> It is widely believed that many Halloween traditions originated from ancient Celtic harvest festivals, particularly the Gaelic festival Samhain; that such festivals may have had pagan roots; and that Samhain itself was Christianized as Halloween by the early Church . Some believe, however, that Halloween began solely as a Christian holiday, separate from ancient festivals like Samhain . </P>

Where did the idea of halloween come from