If set times are posted somewhere and the schedule is not followed, that is poor management. For years I worked at Fletchers and it was my job to get the show started on time, and keep the thing running smoothly. 15 minute set changes with drum kits going up/down, and all that. Yep, been there done that. It is rude to the headliner if they expect to be on at midnight and they are going on an hour later to 1/2 the crowd. I know I would be pissed if I were the headliner. There has to be some level of professionalism, if you post a schedule, keep to it as much as possible. If no one is there for the opener, it could well be no one wants to see the openers. They should have pulled in their friends, if they didn't, why should the other bands suffer? I admit to being an iron fist with schedules, if they are posted, I will keep to them, that is the job of the club, if you can't do that don't post a schedule.