I saw this in my Theatre textbook today: “Interestingly, the division into acts was added after Shakespeare’s day—his plays were performed outdoors during the daytime, so he included no intermissions.” He may well have included no intermissions but I don’t think it was because of illumination.
A few years ago, I wrote some software during a hackathon that proved illumination from candles would have been required in Shakespeare’s day even at outdoor venues such as the Globe. Also, many of the plays were first performed indoors at The Blackfriar’s. This supposition about illumination and Shakespeare is simply wrong.
If I get a chance farther along in my theatre studies, I’d like to take a really long look at this question. I’ll need to delve much deeper into theatre history and into astronomical observation. I think there’s a falsehood that’s been handed down through the years that feels just right enough but which history and science might help us confirm or deny.