It's hard to say. I'm sure if you ask doctors, they'll all tell you that it depends on where you work and your specialty. It really varies from department to department and location so I think the best way to find this answer is to shadow doctors and ask. There is no specific answer. That being said, depending on the department, a doctor's hours can be much longer/more variable than an NPs. An NPs schedule can also vary, but generally they're more likely to have a consistent schedule. If you're concerned about the work schedule going into medicine, you might want to consider PA. PAs have some of the best work-life balance, and it was voted #1 job by US News. That being said, work schedule is very situational. I know a PA who worked 5, 8-hour shifts a week, but went to NYC for a short period of time to be part of a COVID response team. At this temp position, she worked 12 hours, 6 days a week even though she didn't have to so that she could quickly pay off her debt. Now, she's back at her original job, doing the 40 hours. All of this being said, I'd say just shadow doctors/contact them and ask because it's different for everyone! But if you prioritize a consistent work schedule over everything else, medical school residency will be extremely hard for you. You will have 12-24 hour shifts/be on call for several years until you can start practicing independently and solidify a schedule.
The answer is that it varies. Depending on specialty, doctors and NP hours can vary. Also if you are in a specialty that has to take call, that can change your work life balance. At this point and time in my career, I work 30 hours by choice and I don't take call. Working in a 100% office setting is going to have more regular hours than working in a hospital/office setting. Surgeons will have longer hours than a family practice doctor. The best advice to to shadow individuals in the practice setting that you are thinking of going into so that you can have a realistic picture of what their job involves.