Re: What problems do leap seconds *really* create?

. We know we can live with that, as O(log(t)) is equivalent to O(1) for engineering purposes.) Markus -- Markus Kuhn, Computer Lab, Univ of Cambridge, GB http://www.cl.cam.ac.uk/~mgk25/ | __oo_O..O_oo__

Re: What problems do leap seconds *really* create?

John Cowan wrote on 2003-01-30 13:01 UTC: Markus Kuhn scripsit: Unix timestamps have always been meant to be an encoding of a best-effort approximation of UTC. Unix is in fact older than UTC. This is getting slightly off-topic, but Unix slowly evolved and was reimplemented various times

Re: Telescope pointing and UTC

) been asked, what |UT1-UTC| 0.9 s would means for the many thousands of systems that they have already sold? Markus -- Markus Kuhn, Computer Lab, Univ of Cambridge, GB http://www.cl.cam.ac.uk/~mgk25/ | __oo_O..O_oo__

Re: Leap seconds in the European 50.0 Hz power grid

Steve Allen wrote on 2003-01-30 20:58 UTC: On Thu 2003-01-30T12:54:09 +, Markus Kuhn hath writ: The UCPTE specification says that the grid phase vectors have to rotate on long-term average exactly 50 * 60 * 60 * 24 times per UTC day. Obviously the grid frequency shift after leap seconds

Some personal notes on the Torino meeting

and flesh out this concluding recommendation. I left Italy already Thursday evening and I hope we will see the final result here sometimes this or next week. Markus -- Markus Kuhn, Computer Lab, Univ of Cambridge, GB http://www.cl.cam.ac.uk/~mgk25/ | __oo_O..O_oo__

Re: religious concerns

/ http://www.cca.org/woc/felfat/ Markus -- Markus Kuhn, Computer Lab, Univ of Cambridge, GB http://www.cl.cam.ac.uk/~mgk25/ | __oo_O..O_oo__

DRM broadcast disrupted by leap seconds

hour, in discussions the hope was expressed that in practice nobody will notice.] Either having a commonly used standard time without leap seconds (TI), or having TAI widely supported in clocks and APIs would have solved the problem. Markus -- Markus Kuhn, Computer Laboratory, University

Re: DRM broadcast disrupted by leap seconds

chance that there might soon be no more of them. Markus -- Markus Kuhn, Computer Lab, Univ of Cambridge, GB http://www.cl.cam.ac.uk/~mgk25/ | __oo_O..O_oo__

German Time Act of 1978, now available in English

and and discuss the remaining technicalities with their international counterparts via the usual scientific communication channels. Markus -- Markus Kuhn, Computer Lab, Univ of Cambridge, GB http://www.cl.cam.ac.uk/~mgk25/ | __oo_O..O_oo__

Re: preferred months for leap seconds

. Therefore, nobody at IERS has any reason to be missing their New Year's Eve party year after year in order to insert a leap second, because all their work has already been done half a year earlier. Markus -- Markus Kuhn, Computer Lab, Univ of Cambridge, GB http://www.cl.cam.ac.uk/~mgk25/ | __oo_O..O_oo__

Re: mining for data about time

-line syntax (e.g., comma separated values, etc.) that can be parsed trivially with a simple single-line Perl or Awk regular expression. Markus -- Markus Kuhn, Computer Lab, Univ of Cambridge, GB http://www.cl.cam.ac.uk/~mgk25/ | __oo_O..O_oo__

More media coverage: Der Spiegel 2003-08-25

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

Re: name the equinox contest on now

making this work more accessable and therefore useable by a much larger community. Just a thought ... Markus -- Markus Kuhn, Computer Lab, Univ of Cambridge, GB http://www.cl.cam.ac.uk/~mgk25/ | __oo_O..O_oo__

Re: GPS versus Galileo

turf fight between the Pentagon and the EU Commission. Is seems the Temporal Cold War has begun ... Markus -- Markus Kuhn, Computer Lab, Univ of Cambridge, GB http://www.cl.cam.ac.uk/~mgk25/ | __oo_O..O_oo__

Re: GPS versus Galileo

and Aeronautics, Volume 163, American Institute of Aeronautics and Astronautics, Washington DC, 1996. -- Markus Kuhn, Computer Lab, Univ of Cambridge, GB http://www.cl.cam.ac.uk/~mgk25/ | __oo_O..O_oo__

ITU-R SRG7A Turin colloquium proceedings available online

The proceedings and final report of the ITU-R SRG7A Colloquium on the UTC Timescale, Turin, Italy, 28-29 May 2003, have now appeared online at the IEN web site: http://www.ien.it/luc/cesio/itu/ITU.shtml Markus -- Markus Kuhn, Computer Laboratory, University of Cambridge http

Re: ITU Meeting last year

to turn UTC into an interrupt-free physical time scale decoupled from the rotation of the Earth, then it should say so honestly, by defining that UTC will *never* ever leap in any way, neither by a second, nor by an hour. Markus -- Markus Kuhn, Computer Lab, Univ of Cambridge, GB http

Re: ITU Meeting last year

-UTC offset defined instead, then what you describe above is indeed what I would expect to happen with most of them. Unless we give up the notion of local time zones entirely, there would be a clear need to keep them locked to UT1 + offset to within an hour or so. Markus -- Markus Kuhn, Computer Lab

Re: TAI-UT1 prediction

frequency) slowing down roughly linearly, therefore the accumulation of the phase difference being (after integrating) an essentially quadratic function? Markus -- Markus Kuhn, Computer Lab, Univ of Cambridge, GB http://www.cl.cam.ac.uk/~mgk25/ | __oo_O..O_oo__

Re: Time after Time

there, then you have simply misunderstood the entire purpose of the process. Markus -- Markus Kuhn, Computer Lab, Univ of Cambridge, GB http://www.cl.cam.ac.uk/~mgk25/ | __oo_O..O_oo__

Re: Time after Time

John Cowan wrote on 2005-01-23 18:37 UTC: Markus Kuhn scripsit: UTC currently certainly has *no* two 1-h leaps every year. There seems to be persistent confusion on what is meant by the term leap hour. Why? I understand it as a secular change to the various LCT offsets, made either all

Leap-second scare stories

replacing a reasonably frequent minor distruption (UTC leap seconds) with a very rare catastrophically big one (UTC leap hours). Markus -- Markus Kuhn, Computer Laboratory, University of Cambridge http://www.cl.cam.ac.uk/~mgk25/ || CB3 0FD, Great Britain

Re: a system that fails spectacularly

by adding a publication requirement to the ISO 9000 certification process, but I doubt that anyone other than civilian customers would want that. And these standards are not written by civilian customers. Markus -- Markus Kuhn, Computer Laboratory, University of Cambridge http://www.cl.cam.ac.uk/~mgk25

Re: Lighter Evenings (Experiment) Bill [HL]

+ Australia: use local time of Thailand (~ UT + 6.5 h) Sure, the hours of darkness would vary substantially within each of these zones. But they do already *today* for much of the world, thanks to summer/winder. China understood this a long time ago. Markus -- Markus Kuhn

Re: Things to do at about 2005-12-31 23:59:60Z

IF should be sufficient, I'd be happy to help out with the offline demodulation and decoding afterwards. Markus -- Markus Kuhn, Computer Laboratory, University of Cambridge http://www.cl.cam.ac.uk/~mgk25/ || CB3 0FD, Great Britain

Re: HBG transmitted wrong info during leapsecond

Which was also noted at http://wwwhome.cs.utwente.nl/~ptdeboer/ham/sdr/leapsecond.html Various other LF 2005 leap second recordings are listed at http://www.cl.cam.ac.uk/~mgk25/time/lf-clocks/#leapsec2005 Markus -- Markus Kuhn, Computer Laboratory, University of Cambridge http

Re: The real problem with leap seconds

news, and you still cannot even get it reliably from your average local NTP server. (I know, we've already discussed this here, on [EMAIL PROTECTED], on pasc-time-study, and on austin-group-l in *very* great detail, many, many, many times, so I'll stop.) Markus -- Markus Kuhn, Computer Laboratory

Internet-Draft on UTC-SLS

A new Internet-Draft with implementation guidelines on how to handle UTC leap seconds in Internet protocols was posted today on the IETF web site: Coordinated Universal Time with Smoothed Leap Seconds (UTC-SLS), Markus Kuhn, 18-Jan-06. (36752 bytes) http://www.ietf.org/internet-drafts

Re: Internet-Draft on UTC-SLS

) in Appendix A]. Some of these alternatives have caused quite some off behaviour on 1 January in NTP-synced equipment. Markus -- Markus Kuhn, Computer Laboratory, University of Cambridge http://www.cl.cam.ac.uk/~mgk25/ || CB3 0FD, Great Britain

Re: Internet-Draft on UTC-SLS

solution, *if* we accept the premise that civilian time remains tied to UT1. Markus -- Markus Kuhn, Computer Laboratory, University of Cambridge http://www.cl.cam.ac.uk/~mgk25/ || CB3 0FD, Great Britain

Re: Internet-Draft on UTC-SLS

software easily and robustly in a way that is fully backwards compatible with the existing NTP protocol and infrastructure. Markus -- Markus Kuhn, Computer Laboratory, University of Cambridge http://www.cl.cam.ac.uk/~mgk25/ || CB3 0FD, Great Britain

McCarthy point (was: Fixing POSIX time)

planetary motion over many years, the difference matters. Markus -- Markus Kuhn, Computer Laboratory, University of Cambridge http://www.cl.cam.ac.uk/~mgk25/ || CB3 0FD, Great Britain

Re: Internet-Draft on UTC-SLS

Tim Shepard wrote on 2006-01-19 20:29 UTC: Coordinated Universal Time with Smoothed Leap Seconds (UTC-SLS), Markus Kuhn, 18-Jan-06. (36752 bytes) http://www.ietf.org/internet-drafts/draft-kuhn-leapsecond-00.txt This draft bugs me a bit because it changes the length of a second

Re: Ambiguous NTP timestamps near leap second

for most of these cases (but not for the NTP protocol itself). Markus -- Markus Kuhn, Computer Laboratory, University of Cambridge http://www.cl.cam.ac.uk/~mgk25/ || CB3 0FD, Great Britain

Re: 24:00 versus 00:00

on http://en.wikipedia.org/wiki/24-hour_clock where trains arrive at 24:00 but depart at 00:00. http://en.wikipedia.org/wiki/Midnight Markus -- Markus Kuhn, Computer Laboratory, University of Cambridge http://www.cl.cam.ac.uk/~mgk25/ || CB3 0FD, Great Britain

Re: Ambiguous NTP timestamps near leap second

be 00:00:00.0001 instead. Markus -- Markus Kuhn, Computer Laboratory, University of Cambridge http://www.cl.cam.ac.uk/~mgk25/ || CB3 0FD, Great Britain

Re: 24:00 versus 00:00

, where march can be MAR, MCH, MRH, MRC, etc. Markus -- Markus Kuhn, Computer Laboratory, University of Cambridge http://www.cl.cam.ac.uk/~mgk25/ || CB3 0FD, Great Britain