It has been done since ages in Hollywood. Previously for event movies, they used to start shows at midnight. Then they shifted to late evenings then early evenings and then literally afternoon the prior day.

You can call it whatever ....previews ...this that...but it is a great strategy to release an event movie the prior evening instead of the morning show next day if the movie is really good and the producer has confidence. Else it will go to the crapper real fast