[ntp:questions] Re: Monitoring the leap second tonight

Markus Kuhn n06W03+mgk25 at cl.cam.ac.uk
Fri Jan 20 14:03:44 UTC 2006


Ulrich Windl <Ulrich.Windl at RZ.Uni-Regensburg.DE> writes:
|> > Sun Jan 1 00:59:57 CET 2006
|> > Sun Jan 1 00:59:58 CET 2006
|> > Sun Jan 1 00:59:59 CET 2006
|> > Sun Jan 1 00:59:59 CET 2006   <=== leap second occured
|> 
|> Shouldn't the output have been "Sun Jan 1 00:59:60 CET 2006"?

IMHO, there are pretty strong arguments that attempting to implement a UTC
leap this way (i.e., showing the 60 or even repeating the 59) on a computer
clock could be called an undesireable and potentially disruptive engineering
practice. Remember that ITU-R TF.460 was written for pulse-per-second
timecodes, where this makes sense, and not for operating system APIs,
network protocols, etc.

I think, the ITU-R TF.460 idea of a second labeled 60 should not be
implemented in these areas without very careful thinking about the
consequences. There are much less troublesome conventions possible
for performing the 1-second UTC adjustment in a computer clock:

  http://www.ietf.org/internet-drafts/draft-kuhn-leapsecond-00.txt

Markus

-- 
Markus Kuhn, Computer Laboratory, University of Cambridge
http://www.cl.cam.ac.uk/~mgk25/ || CB3 0FD, Great Britain




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