jet lag clock

Something was lost in translation there, I think...

What I want is an app that tells me what time my body thinks it is.

Example
I travel from Stockholm to Los Angeles. My body starts adjusting as soon as I get there, but two days later it's still not in sync with local time. My friend looks at me and says "You still look tired". I show him the JLC and he simply nods. "They should have called that app the body clock daemon instead. Silly name, really."

Wouldn't unticking "adjust clock automatically" in Settings do the same thing?

No.

When I arrive in LA my body is still on CET. But then the body-time starts drifting towards local time. A rule-of-thumb states that it drifts about an hour per day. If the drift is linear then the body-time could be calculated.

Staying on CET in LA would not be the same thing.

And how do you intend to tell the app what your perceived body clock time is? Update it manually every morning? Or is it supposed to take a wild guess?

I mean, an hour per day is a very rough guess. I've had times when I adjusted overnight. Other times when I did not at all even after a week :)

I guess that's where the body clock daemon comes in. The daemon could read the time zone data a number of times per day and keep simple statistics to make the calculations. ...I'm just guessing here.