[ntp:questions] Re: Leap second talks are postponed

David J Taylor david-taylor at blueyonder.co.not-this-bit.nor-this-part.uk.invalid
Mon Nov 21 17:47:58 UTC 2005

David L. Mills wrote:
> David,
> The implementations including my code do not step the clock, just stop
> if or allow it to progress slowly during the leap second itself. If
> what you mean by slewing is to force the clock to amortize the second
> at "normal" slew rate, say 500 PPM, then the clock would be in error
> very close to one second following the leap and take the better part
> of one hour to resume expected accuracy. Meanwhile, NTP would scream
> and holler because the step threshold would be exceeded. Of course,
> should you be concerned about step corrections and forbid them as
> configuration option, your applications would have to be content with
> the large error during the amortization interval.


I suspect we're going round in circles here - I'm not talking about your 
code but how it has to be implemented on Windows.  I don't know the exact 
details, but I believe that the present code steps the clock, rather than 
(as some Microsoft code apparently does), simply set a very large clock 
slew so that within a second or two, the leap second has been 
accommodated.  I.e. the clock is running at something like double (or is 
it half?) speed for a very short time.

I'm sure those implementing the Windows port will be on top of it within a 
couple of weeks (at least I hope so!).


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