Also, A Christmas Carol by Charles Dickens takes place in one night
Oops, I forgot you said: I'd like to avoid "and it was all a dream", time travel, or similar plot devices if possible
Wow, it's really hard to think of books that only take place in a few hours. The only ones I can think of take place over the course of a day. Yeah, I guess reading plays would be your best bet
Try the classical Greek tragedies—one of the requirements of the genre is that the action is supposed to take place in less than a day (Aristotle’s “unity of time”).
I haven’t read it yet, but Martin Riker’s novel The Guest Lecture apparently takes place in the mind of a professor lying awake in bed the night before she’s supposed to deliver a lecture.
Other people have already said Ulysses and Mrs Dalloway, both modernist classics that take place in a single day. There are a couple of other examples of similar novels, but the only one that springs to mind right now is a deeply annoying experimental 'novel' called Fidget by Oliver Goldsmith, which I don't recommend at all. He wore a tape recorder and spoke out loud describing everything he did that day, then transcribed it all and that's the book. If you do decide to read it, don't say I didn't warn you.
I don't know if this will count for you, but there's a hypertext novel called 253 by Geoff Ryman which IIRC takes place over just a couple of minutes, with very short chapters describing the thoughts of each of the 253 passengers on board a train. He did later also publish a print version.