The same general structure, in a Military SF context of progressively learning to be a better soldier with each iteration, is central to the film Edge of Tomorrow ( 2014).

(This film's similarity to '12:01 PM' and 12:01 PM above is sufficiently strong that Lupoff and his director seriously contemplated legal action.) Further stories dealing with the repeated replay of a single day are 'Doubled and Redoubled' (February 1941 Unknown) by Malcolm Jameson, 'Friday, the Nineteenth' (Summer 1950 F&SF) by Elisabeth Sanxay Holding (1889-1955) and One Fine Day ( 1981) by Leon Arden вЂ“ who did in fact sue the makers of Groundhog Day over similarities, though without success.

Ken Grimwood's Replay ( 1987) offers its protagonist the repeated opportunity to relive the 'same' life with knowledge of past iterations, and the film Groundhog Day ( 1993) does similarly with a single recurring day: escape from the loop requires learning to steer a perfect course through replayed time. Successive dreams in Ole Luk-Oie's The Defence of Duffer's Drift ( 1904 chap) as by Backsight Forethought reiterate a Boer War skirmish with steadily increasing understanding and improvement of small-unit tactics against a larger force. When memories of past circuits of a time loop are permitted, there is the possibility of transforming the imprisoning circularity into an upward spiral, a learning curve. The cast of Jack Skillingstead's Life on the Preservation ( 2013) is trapped in the domed City of Seattle, forever recycling the same day. In Philip K Dick's 'A Little Something For Us Tempunauts' (in Final Stage, anth 19 ed Barry N Malzberg and Edward L Ferman), the cycle may be ultimately inescapable there is a grim suspicion that the US chrononauts' suicidal attempt to disrupt the obscurely sensed time-loop has in fact brought it into being. Richard A Lupoff's '12:01 PM' (December 1973 F&SF) traps its protagonist in the same repeated hour, always resetting to the time of the title with even death offering no release this became a short Oscar-nominated film, 12:01 PM ( 1991) directed by Jonathan Heap, and a longer made-for-tv feature: 12:01 ( 1993) directed by Jack Sholder (again see 12:01 PM). One of the many temporal complications of Keith Laumer's Dinosaur Beach ( 1971) sees the protagonist enter a closed time loop where an older and wiser version of himself insists that (as he had been uselessly told by his predecessor, and so on back through an unknown number of cycles) the new arrival must kill his elder self to break the loop. A Mad Scientist entraps his victim and indeed the whole world in a reiterated New Year's Eve in the Shadow radio segment 'The Man Who Murdered Time' (1 January 1939). This is not so in Anthony Armstrong's early comic-fantasy example 'The Prince's Birthday Present' (in The Prince Who Hiccupped and Other Tales, coll 1932), whose ungrateful recipient of three wishes вЂ“ multiplied by recursive wishing to an indefinite number вЂ“ is finally unwise enough to ask that he may relive the last, particularly enjoyable half-hour the replay of course includes this fatal wish. The present entry discusses the form of time loop in which, typically, periods of time are repeated and re-experienced by a character's consciousness: there is often some hope of breaking out of the useless cycle of repetition.

A classic form of Time Paradox (which see) comes into being when the chain of causality eats its own tail to leave a circular sequence of events with no logical starting point, as in Robert A Heinlein's two famous examples: 'By His Bootstraps' (October 1941 Astounding as by Anson MacDonald) and 'All You Zombies вЂ“' (March 1959 F&SF). The theme of a closed loop in Time appears in sf in two distinct senses.

Temporal causality loop