Most people also don't set an alarm on their phone for 4:59 at which point they leave no matter what is happening. Not saying the GP is that person, but there are certainly extremes on both ends of the spectrum (working 80 hours a week v. refusing to work 8h 0m 1s under any non-emergency circumstance no matter what), and I've worked with both of them and neither are very enjoyable to be around.

I've had meetings scheduled that go past the end of my day. Or on a day where I work a different schedule (6-2 or 10-6 or whatever) a normal meeting outside of my schedule for the day. Sometimes professionalism dictates you suck it up and work more than 8 hours in a day. If you have a reasonable manager, just work less than 8 the next day! It's not that big of a deal, and to say "well I'll be in for 8 hours tomorrow so I'm leaving now you can go to hell" is not a reasonable way to handle it.

I don't think it has anything to do with fear. It has to do with understanding that life (yes even non-emergency events) don't always fit into a neat 8-hour or 9-hour window, and adjusting yourself accordingly.

I've often worked 10 or more hours in a day for non emergency reasons. I've often worked 5 hours or less in a day to make up for it. I still manage a roughly 40 hour or less work week and it's no less "sane" than any other approach.

I agree with everything you've said, but how do you feel about your phone ringing at 2am on a Sunday?

Is it reasonable to come in and do a few hours then, and just do a few less on Monday morning?

I personally am happy to work the odd late day, even stay late with the team, grab a pizza, etc.

Getting calls in the middle of the night, or on the weekend, or on a holiday is a completely different thing that requires compensation, no exceptions.

Yeah, people need to be less uptight about this in general. Once in a while you'll have an appointment or a flight or something that requires you to leave at 5:00:00 sharp, and that's cool as long as it's not excessive, but most of the time employees should expect to leave anywhere between 4pm and 6pm just based on how the day is going, what meetings are scheduled, etc.