Hollywood kids themselves about why people aren’t going to the theater as much as before. Personally, I’m fed up with being subjected to their flood of ads before showtime, which is tantamount to them stealing my time without my permission, let alone without giving me the courtesy to choose whether to arrive there before the film starts or before the commercials start. Actually, sometimes I may be willing to squander the time to watch their commericals if I have nothing else going on, but for them to take this freedom of choice is disrespectful of their audiences.
Regardless, toward creating a more informed public and audience, it would be great if for every theater you list in your Showtimes listings, it also stated something like “Films at this theater have been reported to typically begin 15 (or 20) minutes after the posted times.”
For you to get this information you could be straightforward and ask the theaters themselves to provide it. Or you could post a tally based upon signed customer e-mails, which, unless the sender objects, might be forwarded to the theaters so they can handle their own customer service issues.