National Science Fiction Day is unofficially celebrated by many science fiction fans in the United States on January 2, a date that was chosen to correspond with the official birthdate of famed science fiction writer Isaac Asimov.
While not an official holiday of any sort (in the sense that it is not recognized or declared by any government), National Science Fiction Day is given some degree of credence by its recognition by organizations such as the Hallmark Channel and by the Scholastic Corporation.
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National Science Fiction Day Wikipedia(Text) CC BY-SA