Earlier quoted context omitted.
I really don't think you've ever seen BSD return in milliseconds after a 1-second sleep. Respectfully, I think you're pretty much just wrong.
Well, that is not what I meant at all, I meant that I've seen BSD return in say 2 microseconds after calling usleep(1). But that's usleep not sleep, which is the inaccuracy I was admitting to in the first place.
Ok, but (a) this article is talking about literally POSIX sleep(3), and (b) there is a ton of confusion on this thread about whether sleep is ms-denominated or seconds-denominated.
Sorry to pile on you, though.