Midnight movie is a term rooted in the tradition that emerged in the 1950s. Local television stations around the United States would air low-budget genre films as late-night programming, often with a host delivering asides.
In the early 1970s, the midnight screening of unusual movies began in a few cities, particularly New York City, and eventually spread across the country. The screening of low-budget, non-mainstream films at midnight was aimed at building a cult film audience, encouraging repeat viewing and social interaction in what was originally a countercultural setting.
With the huge success of The Rocky Horror Picture Show and the changing economics of the film industry, the midnight movie phenomenon was forever changed and the midnight movie then became a more of a campy experience.
The term midnight movie is now most often used in two different ways: as a synonym for B-movie, due to the low quality of late-night movies both theatrically and on TV, and as a synonym for cult films.
But even today you can still find midnight movie experiences, some film festivals have a “Midnight Madness” program reserved for cult films. You won’t be able to find these at most mainstream movie theaters though, however, some do occasionally have a Rocky Horror night.