Theater3232 said: "I guess they don't care if the paying audience finds Monday 8pm to be inconvenient, which is why they need to heavily discount these performances. Just start the rehearsals an hour earlier to match the hours of most working professionals. If Wall Street can start by 8am, so can theater rehearsals.
Actually, no. They can't. First of all, there are often tech things that are taken care of in the morning that require having the stage clear of actors. There are also union rules about how much time off is needed between breaking the night before and starting the next day. And I think, if I remember correctly, there is a cap on the number of hours of rehearsal can be done on a performance day (this is Equity specific). So you have tech work in the morning, then hopefully a lunch break, then a rehearsal with the cast to implement any changes, dinner break, and then the show.
Schedules can get a bit weird during previews for a variety of reasons, so sometimes performing on Monday is the way to get an 8 show week in (or 7 show - depending on schedule).
As for not caring about an audience attending, getting an additional performance in before opening can be worthwhile even if sales aren't as high as other nights. Many GMs budget for "Preview Losses" in their production budget to cover this kind of thing.
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