Even the bathrooms have motion sensors on the lights. The sensors in the bathroom must be on pretty long timers, though, because they've never gone off while I've been sitting in a stall, hidden from the sensor. In contrast, the lights in my office go off a few times a day, if I don't move around at my desk enough.
I can tell when it's quitting time, because lights in the bathroom actually have a chance to turn off. Usually this happens around 5. Today must be a Friday, because they were off by 3:30.
Now if you'll excuse me, I have to stand up and wave my arms around - the lights in my office just went off.