If you’re a character in The Ring (’02) and you watch Samara’s psychically imprinted video cassette, you will receive shortly thereafter a phone call. “Hello,” you’ll say, because that’s how people answered the a phone at the turn of the millennium, and a voice will reply, “Seven days.” You’ll either be perplexed and/or dismissive — “a prank call” — or you’ll shudder because you know you have but seven days to live unless you can overlook the ethical — nay, moral — implications and show the video to someone else who’ll then themselves have a week to resolve the same dilemma.
Night (or Curse) of the Demon (’57) is about an easily insulted warlock who murders rivals with a slip of paper inscribed with runic characters; if said paper is passed by the warlock without the victim’s knowledge, the victim is pursued by a demon for three days, then killed — unless he can return the paper to the warlock without the warlock’s knowledge. Maybe you’ve sung along with Richard O’Brien and Miss Strawberry Time’s lips at the start of The Rocky Horror Picture Show (’75): “Dana Andrews said prunes gave him the runes / And passing them uses lots of skill.” You’ll be happy to know that Dana Andrews, before his three days are up, passes the runes to the warlock.
More… “There’s a Ghost Behind You”