Re: Predictable Internet Time
Stewart Bryant <stewart.bryant@gmail.com> Tue, 03 January 2017 18:35 UTC
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Subject: Re: Predictable Internet Time
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From: Stewart Bryant <stewart.bryant@gmail.com>
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Date: Tue, 03 Jan 2017 18:35:03 +0000
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Yes, the system should use a leap-second-free constant-duration-seconds time for everything. It is only humans that need the variable jumpy version of time presented to them, and that is a UI issue. - Stewart On 03/01/2017 18:25, Joe Touch wrote: > We really need to separate the frames of reference of time - there's no > need for smear for internal "seconds since epoch" time. Smear only > renders UTC values incorrect,, which is an invitation to have financial > and legal transactions fail and report local events (e.g., rates, etc.) > incorrectly. > > We shouldn't propagate an incorrect solution. > > Joe > > > On 1/3/2017 6:08 AM, Tony Finch wrote: >> Joe Touch <touch@isi.edu> wrote: >>> Smearing leads to differing interpretations of elapsed time for two reasons: >>> >>> 1) smearing isn't unambiguously specified >>> 2) smearing doesn't match the clock standards set by the ITU (who >>> defines UTC) >> Since leap smear is becoming more popular, it would be sensible to try to >> get a consensus on the best way to do it if you do it. Clearly >> organizations that do leap smear think (2) leap seconds are too much >> trouble so it's better to diverge from official time in a controlled >> manner. >> >> To clear up (1) there are a few technical choices on which people seem to >> be working towards some kind of agreement... >> >> * If you centre the smear period over the leap second, your maximum error >> from UTC is 0.5s, which seems to be preferable to starting or ending the >> smear period on the leap second >> >> * Linear smear works better than sigmoid smear, since it minimizes the >> rate divergence for a given smear period, and NTP's algorithms react >> better >> >> * Longer smear periods are better, because they give NTP more time to >> react to the rate change, and they minimize the rate difference >> >> It looks to me like a 24h leap smear from 12:00 UTC before the leap to >> 12:00 UTC after the leap has a good chance of becoming more popular than >> other leap smear models. >> >> Tony.
- Re: Predictable Internet Time Nico Williams
- Re: Predictable Internet Time Toerless Eckert
- Re: Predictable Internet Time Patrik Fältström
- Re: Predictable Internet Time Nico Williams
- Re: Predictable Internet Time Phillip Hallam-Baker
- Re: Predictable Internet Time Joe Touch
- Re: Predictable Internet Time Joe Touch
- Re: Predictable Internet Time Nico Williams
- Re: Predictable Internet Time Joe Touch
- Re: Predictable Internet Time Phillip Hallam-Baker
- Re: Predictable Internet Time Joe Touch
- Re: Predictable Internet Time Phillip Hallam-Baker
- Re: Predictable Internet Time Izaac
- Predictable Internet Time Phillip Hallam-Baker
- Re: Predictable Internet Time sandy
- Re: Predictable Internet Time Phillip Hallam-Baker
- Re: Predictable Internet Time Joe Touch
- Re: Predictable Internet Time Phillip Hallam-Baker
- Re: Predictable Internet Time Patrik Fältström
- Re: Predictable Internet Time Eliot Lear
- Re: Predictable Internet Time Patrik Fältström
- Re: Predictable Internet Time Eliot Lear
- Re: Predictable Internet Time Tony Finch
- Re: Predictable Internet Time Phillip Hallam-Baker
- Re: Predictable Internet Time Cyrus Daboo
- Re: Predictable Internet Time Jared Mauch
- Re: Predictable Internet Time Stewart Bryant
- Re: Predictable Internet Time Phillip Hallam-Baker
- Re: Predictable Internet Time Phillip Hallam-Baker
- Re: Predictable Internet Time Cyrus Daboo
- Re: Predictable Internet Time Joe Touch
- Re: Predictable Internet Time Stewart Bryant
- Re: Predictable Internet Time Joe Touch
- Re: Predictable Internet Time Stewart Bryant
- Re: Predictable Internet Time Stewart Bryant
- Re: Predictable Internet Time Cyrus Daboo
- Re: Predictable Internet Time Phillip Hallam-Baker
- Re: Predictable Internet Time Ted Lemon
- Re: Predictable Internet Time Stewart Bryant
- Re: Predictable Internet Time Eliot Lear
- Re: Predictable Internet Time Joe Touch
- Re: Predictable Internet Time John C Klensin
- Re: Predictable Internet Time Phillip Hallam-Baker
- Re: Predictable Internet Time Pete Resnick
- Re: Predictable Internet Time Cyrus Daboo
- Re: Predictable Internet Time Joe Touch
- Re: Predictable Internet Time Phillip Hallam-Baker
- Re: Predictable Internet Time Phillip Hallam-Baker
- Re: Predictable Internet Time Tony Finch
- Re: Predictable Internet Time Tony Finch
- Re: Predictable Internet Time Joe Touch
- Re: Predictable Internet Time Joe Touch
- Re: Predictable Internet Time Phillip Hallam-Baker
- Re: Predictable Internet Time Paul Eggert
- Re: Predictable Internet Time Tony Finch
- Re: Predictable Internet Time Phillip Hallam-Baker
- Re: Predictable Internet Time Patrik Fältström
- Re: Predictable Internet Time Joe Touch
- Re: Predictable Internet Time Joe Touch
- Re: Predictable Internet Time Tony Finch
- Re: Predictable Internet Time Joe Touch
- Re: Predictable Internet Time Joe Touch
- Re: Predictable Internet Time Philip Homburg
- Re: Predictable Internet Time Tony Finch
- Re: Predictable Internet Time Joe Touch
- Re: Predictable Internet Time Tony Finch
- Re: Predictable Internet Time Joe Touch
- Re: Predictable Internet Time Patrik Fältström
- Re: Predictable Internet Time Eliot Lear
- Re: Predictable Internet Time Harald Alvestrand
- Re: Predictable Internet Time Stewart Bryant
- Re: Predictable Internet Time Joe Touch
- Re: Predictable Internet Time Leif Johansson
- Re: Predictable Internet Time Eliot Lear
- Re: Predictable Internet Time Leif Johansson
- Re: Predictable Internet Time Phillip Hallam-Baker
- Re: Predictable Internet Time Joe Touch
- Re: Predictable Internet Time Patrik Fältström
- Re: Predictable Internet Time Nico Williams
- Re: Predictable Internet Time Joe Touch
- Re: Predictable Internet Time Michael Breuer
- Re: Predictable Internet Time Nico Williams
- Re: Predictable Internet Time Joe Touch
- Re: Predictable Internet Time Tony Finch
- Re: Predictable Internet Time Joe Touch
- Re: Predictable Internet Time Joe Touch
- Re: Predictable Internet Time Patrik Fältström
- Re: Predictable Internet Time Joe Touch
- Re: Predictable Internet Time Nico Williams
- Re: Predictable Internet Time Nico Williams
- Re: Predictable Internet Time Nico Williams
- Re: Predictable Internet Time Nico Williams
- Re: Predictable Internet Time Harald Alvestrand