Re: [LEAPSECS] how to reset a clock

From: Peter Bunclark <psb_at_AST.CAM.AC.UK>
Date: Thu, 4 Jan 2007 10:53:22 +0000 (GMT)

On Thu, 4 Jan 2007, Tony Finch wrote:

> On Thu, 4 Jan 2007, Zefram wrote:
>
> > The solution is to just let the clock run, never adjust it, and treat
> > it as an independent seconds count. You don't care about it showing
> > the wrong time, because you don't treat its output as an absolute time.
> > Instead, collect your data on how far out it is (or rather, what absolute
> > time -> output function it is computing) and add the epoch in software.
> > Any number of users of the same clock can do this without treading on
> > each other's toes.
>
> I think that's what I was suggesting :-)
>
> Tony.

Indeed isn't this Rob's ship's chronometer?

Also in the context of the mythical device which has to run many years
into the future without referring to external leap-second tables, when
interaction is eventually resumed you have more chance of recovering the
"true" value of timestamps if it had a chronometer on board and not an
incorrectly-set UTC clock. If contact with the device never is recovered,
why did it matter what it thought the time was?

Peter.
Received on Thu Jan 04 2007 - 02:53:51 PST