I can sometimes predict the time of day without looking at my mobile or PC. I left my room at 1:34 A.M. just now to deposit cash in my bank's ATM (they cheaped out and replaced the nearby CDM with an ATM). It's a 15 minute brisk walk away. So I came back, did some squats, went to pee and while doing that, I think it should be 2:30 A.M. by now. It was actually 2:20 A.M. Not bad, right?