Internal clock

Aloha e Cecil ~ I stopped wearing a watch 20 years ago and since then have discovered that I can usually (90% of the time) tell the time within 15 minutes. This happens first by intuition - i.e. the correct time pops into my head immediately after I wonder what it is. Then I deduce how correct it is by the light in the sky, shadows, what I’ve been doing since I last knew the correct time, etc. I know what you’re thinking - so what? But I recently discovered I can now also tell the time in the middle of the night with similar accuracy. So my question is, how common is this ability, has anyone ever studied it, and how am I/are we doing it?
signed
Chrono-Lisa in Honolulu

Had a coworker that used to have a clock in his hardhat. He’d use his cap to shade the sun, and always “knew” what time it was.

My guess is, since there’s a clock nearby that you can look at to check your estimate, you subconciously looked at it in the past 15 minutes.

Nah, I have this ability too. I can wake up in the middle of the night and say “it’s probably about 3:30” and be within 15 minutes probably 95% of the time. I never set an alarm clock unless I need to get up extraordinarily early, maybe traveling on business or something like that. The odd time that I do wake up and find out it’s, say only 3:00 A.M. when I think it must be about 5:00 I smile a blissful smile and return to dreamland.

During the day there’s just way too many reference points though: computer, phone, cell phone, car, sun, traffic, radio… It’s impossible not to know the time while awake.

Circadian Rhythm is the term for one aspect of it, the waking up at the same time without an alarm, for example.
Ooh, Band Name! Beatcha to it.

I always wake up a couple of minutes before my alarm is due to go off, even if I have set it for an unusual time.

<AOL>Me Too!</AOL>

I’m accurate to less than 15 minutes pretty much all the time, as long as I get an accurate ‘fix’ after I wake up from sleep.

My wife has no time sense whatsoever and gets exasperated when she’s looking for the time and I pop off “Oh, it’s 7:40”, and she goes and checks and finds I’m right :).

But she likes playing with my mind. I need that first fix when I wake up or I’m off-kilter all day. When she’s feeling vindictive, she’ll re-set the clock, wait for me to wake up and notice what time it is, then set it back to normal. For the rest of the day, I’m all screwed up, while she chortles and laughs and has a fun time with it. But I’m only off by the difference she set the clock to, so I still have a partial last laugh.

Due to this, we have concluded that I have no innate time-keeping ability, but rather, have a duration sense that I unconsciously use. This fits with my thought processes when I’m trying to figure out what time it is (when I notice them, that is): I tend to think, “Hmm, it was 6:15 when I woke up, it’s been about, oh… 2 hours since then, it must be 8:15.”

For time, I’m useless.

For direction, I’m very good. I can nearly always judge “north” within a few degrees, even inside buildings, and at night (with typical light pollution).