Media holidays are days whose flighting schedule features television programming so entirely overwhelming that scheduling anything new against them is broadcasting suicide. The Super Bowl is the best example of this - new programming that would normally air on that Sunday is put off for a week so as to keep viewers from choosing between the sporting event of the season and their favorite television program, a choice that wouldn't go well for the competing networks.

A side effect of this is the fun had in seeing what networks are running in the place of their normal programming - you'll find tons of movies or marathons of flagship programs, which are normal and to be expected, as well as programs the networks are trying to quietly bury.