I don’t know who’s in charge of deciding these things, but according to the Popcorn Board it’s National Popcorn Day.
Some suggest the day is marked whichever day the Super Bowl is held, but you don’t need a super bowl: you can order a small, medium or large at your local movie theater, where it’s popcorn day every day.
Of course, there’s alway October, which, thanks to MPAA chairman and former Agriculture Secretary Dan Glickman, is National Popcorn Month.