It is too hard to create illusion while the sun is up. The sleight of hand that occurs when creating the illusion of a reality on the stage requires dark and shadows and mystery. The wrong kind of light will expose all the little tricks and illusion for what they are....make believe. In daylight a costume that sparkles and gleams under the lights of performance, will be revealed to be a bit shabby, kind of tacky, and no longer beautiful. You might see the tears and patches of a well-used costume, the repairs made with thread that doesn't quite match, the safety pin that replaces a missing button. Things that are invisible under stage light, become glaringly obvious in the bright light of day. The walls of a seemingly impenetrable fortress will be revealed to be nothing more than cleverly painted flats or even Styrofoam or cardboard. Anytime you try to create a set, a character, a costume, or a situation that seems real but really isn't, you are asking for a huge suspension of disbelief from everyone in the audience. The audience sits in the darkened theater with stage light directed only where it helps the illusion. The stage pops into reality, but the rest of the space visible to the audience remains completely dark and quietly disappears.
There are, of course, performances that are matinees, but those performances are always in a theater just as dark as it would be at an 8:00 show. The theater staff must completely block out any source of natural light that might spill into the theater and detract from the illusion on the stage. For the performers, leaving the theater after a show and emerging into bright daylight can be disconcerting at best. We do it to maximize audiences and revenue, but most actors don't like it. It just feels wrong. The energy level is off. The reactions of the audience are usually diminished and the whole experience just doesn't feel quite right.
Most of the time rehearsals are done at night as well; at least in the area of volunteer, community theater entities. Mostly this is because the cast and crew all have "real jobs" and a "real life" which take place in the daytime. There are times when the luxury of a nighttime rehearsal is just not possible and we suck it up and make do with an afternoon rehearsal. But a certain number of night time rehearsals are really essential to take advantage of all the benefits of the night that allows the creation of that illusion.
What theater does not do well is mornings! It is just wrong in every possible way. Most theater people seem to be night owls, so mornings are their least favorite times of day. Not only do you not have good energy, your creativity, coordination, attention span, voice, agility, timing, and memory is just not there either!
And the absolute WORST thing is having a rehearsal scheduled early in the day for an energetic musical with lots of dance!
Like the one I had today....that required an 8:00 AM rise (after only 5 hours sleep), a 20 minute drive to the rehearsal space, for a start time of 9:00 AM and lasting until 12:00 Noon!!!
Really, that just sucks! I'm lucky I didn't fall off the stage and break my neck!
9:00 AM, indeed! Honestly, the things I do for love of theater! lol!