Ah, I probably misread the comment a bit. I read it as working 7am to past midnight is rare, making 7am to midnight (or just before) normal. But you're probably right in that what was meant was that there are other, more sane working hours (not defined in the comment) that are the normal conditions.

But yes, to agree with the sibling comment, I'd prefer to never have any doctor in any hospital seeing a patient after they have been working for 17 or more straight hours.

I don't really care how rare it is; I never want to be treated by someone who's been going for more than 8 hours, much less someone who's been going for 17.