Halloween has long been the basis for horror celebrations, but it was made canonical for horror films with John Carpenter’s debut film, Halloween (1978), which uses the holiday as the basis for a supernatural Michael Myers to take vengeance on naughty teenagers. The origin of Halloween is Samhain, one of four Celtic cross-quarter days. The other three, one of which already has an iconic horror film associated with it, are Imbolc (February 2), Beltane (May 1), and Lughnasadh (August 1). Cross-quarter days fall roughly midway between the solstices and equinoxes, each of which also has ancient religious celebrations. The iconic cross-quarter horror film mentioned is, of course, Robin Hardy’s The Wicker Man (1973), and it is set during the time of Beltane.
Apart from seventies styles, The Wicker Man has held up remarkably well. Sergeant Howie, a Scottish police officer, is lured to Summerisle, a remote Hebridean island, to investigate a missing child. He’s been set up, however, by the islanders who need an outsider to sacrifice on their May Day celebrations. Although they never call the holiday Beltane, that is the title of the Gaelic spring festival that dates back to the tenth century. The Wicker Man has received accolades that have grown over the years. It’s been a kind of gold standard for intelligent horror.