> "Warner" == M Warner Losh writes:
Jim> Of those who do, how many do not use networking to keep their clock?
Warner> All of them.
Warner> Control applications for timing systems for LORAN-C slaved to
Warner> GPS *DO* care about time of day (but not local time of day),
Slaved to gps == use
James Cloos wrote:
>Obviously GPS needs to provide quicker almanac sync.
There used to be a notable problem with GPS that all the satellites
transmitted the almanac in unison. This is highly redundant, and
means that the receiver has to wait the full 12(?) minutes to compile a
complete almanac.
In message , Rob Seaman writes:
>So now we're into legal analogies?
No.
But if you do not make a credible case that something is being
overlooked, nobody is going to waste time on your proposed process
to look for things that are being overlooked.
If you could come up with just a single credibl
In message , Rob Seaman writes:
>You may disagree with his premises, but the request was for candidates
>for completely standalone systems requiring high precision clocks.
No, the request was for systems that could not have software updates
applied willy-nilly every six months.
--
Poul-Hen
In message <000301c963cd$0476cd70$0d6468...@com>, "christopher hoover" writes:
>> Everything relating to the power-grid load/supply distribution,
>> that means control of power-plants, transformers and switching
>> stations.
>
>The power grid does not necessarily require (fully) isochronous operati
On Sat, 20 Dec 2008, Steve Allen wrote:
>
> Please identify the operations which need one second predictability
> over a time span of six months.
Anything that needs to exchange time stamps with other systems that are
both accurate and specified in some variant of UT (UTC, POSIX time, NTP
time, et
On Fri, 19 Dec 2008, Rob Seaman wrote:
>
> To synchronize two clocks (Earth and Lunar in this case), you can adjust
> the rates on one end or the other, or you can reset the zero point of
> one or the other on some sort of schedule. Additionally, if the
> differential rates continue to vary, then
>> Please explain why changing the name of the broadcast time scale
>> to TI and putting UTC and the leap seconds into zoneinfo does
>> not satisfy all requirements of the need for uniform time scale.
>
>You keep asking this question and we keep explaining that it breaks
>too much software.
>
>Tony
Tony Finch wrote:
> The local atomic clocks on the Moon or Mars will not run at the
>same rate as a time signal transmitted from the Earth.
More due to being at high altitude than due to relative motion, I believe.
If you're concerned about local interval time, with a sufficiently heavy
em
In message <49513.1229953...@uk2.net>, Peter Vince writes:
>I am trying to clarify in my mind a couple of proposals, one of which is
>having no more leap-seconds in the civil (broadcast)
>time scale. I'm sorry, I must have missed your messages where you said that a
>lot of software would fail
On Mon, 22 Dec 2008, Peter Vince wrote:
>
> I am trying to clarify in my mind a couple of proposals, one of which is
> having no more leap-seconds in the civil (broadcast) time scale. I'm
> sorry, I must have missed your messages where you said that a lot of
> software would fail in that scenario
On 22 Dec 2008 at 14:03, Poul-Henning Kamp wrote:
> This does not fly because a lot of systems are legally mandated to
> use the UTC timescale.
And some laws in some places mandate Greenwich Mean Time, or lots of
other things. No matter what is done with time scales in the future,
it's going t
Tony Finch wrote:
On Fri, 19 Dec 2008, Rob Seaman wrote:
To synchronize two clocks (Earth and Lunar in this case), you can
adjust
the rates on one end or the other, or you can reset the zero point of
one or the other on some sort of schedule. Additionally, if the
differential rates continu
I wrote:
>Tony Finch wrote:
>> The local atomic clocks on the Moon or Mars will not run at the
>>same rate as a time signal transmitted from the Earth.
>
>More due to being at high altitude than due to relative motion, I believe.
I've just found this relevant graph on Wikipedia:
http://up
On Mon, 22 Dec 2008, Zefram wrote:
>
> http://upload.wikimedia.org/wikipedia/commons/9/98/Orbit_times.png
Cool, thanks for that and the interesting details in your other post.
Tony.
--
f.anthony.n.finchhttp://dotat.at/
WIGHT PORTLAND PLYMOUTH: VARIABLE BACKING SOUTHEAST 3 OR 4, OCCASIONALLY
On Dec 22, 2008, at 7:22 AM, Daniel R. Tobias wrote:
On 22 Dec 2008 at 14:03, Poul-Henning Kamp wrote:
This does not fly because a lot of systems are legally mandated to
use the UTC timescale.
And some laws in some places mandate Greenwich Mean Time, or lots of
other things. No matter what
In message <037ba1cd-da84-4ae9-8623-657f4cf8e...@noao.edu>, Rob Seaman writes:
>3) My own point of view focuses on the requirements for "wall
>clocks". Civil timekeeping has (heretofore) been mean solar time
>[...]
You mean "has been within a couple of hours of mean solar time" ?
>4) The IT
On Mon 2008-12-22T14:10:25 +, Tony Finch hath writ:
> The code to implement this has in fact already been written, 15 or more
> years ago, but no-one uses it because it breaks too much stuff.
I am aware of the interesting breakages that happened when
zoneinfo files were retroactively modified
In message <20081222160145.gb7...@ucolick.org>, Steve Allen writes:
>If getting leaps out of the broadcast time scale is the principal and
>urgent *technical* goal [...]
No, the principal goal is make sure all UTC days have exactly 86400
seconds, playing games with the names of timescales will no
In message:
James Cloos writes:
: My point is that the majority of systems which care about timing and
: which can not get almanac data to correlate an interval since an epoch
: with human time-of-day do not, in general, really need the latter.
I see that you've stated this point, bu
Poul-Henning Kamp wrote:
Rob Seaman writes:
3) My own point of view focuses on the requirements for "wall
clocks". Civil timekeeping has (heretofore) been mean solar time
[...]
You mean "has been within a couple of hours of mean solar time" ?
No. I mean "mean solar time". As explained,
On Mon, 22 Dec 2008, Steve Allen wrote:
>
> I am aware of the interesting breakages that happened when zoneinfo
> files were retroactively modified to be inconsistent with POSIX.
> Clearly that change cannot be done for past history.
It can't be done for future history either, because it breaks in
Poul-Henning Kamp wrote:
There is one (major) problem: software does not grok leapseconds.
If my car fails to grok gasoline, I fix the car. Leap seconds (or the
equivalent) are simply a fact of life on a tidally slowing orb. If
you wish to eliminate the overhead of managing leap seconds
Poul-Henning Kamp wrote:
In message , Rob
Seaman writes:
You may disagree with his premises, but the request was for
candidates
for completely standalone systems requiring high precision clocks.
No, the request was for systems that could not have software updates
applied willy-nilly ever
In message:
Tony Finch writes:
: On Mon, 22 Dec 2008, Peter Vince wrote:
: >
: > I am trying to clarify in my mind a couple of proposals, one of which is
: > having no more leap-seconds in the civil (broadcast) time scale. I'm
: > sorry, I must have missed your messages where you sai
On Mon, 22 Dec 2008, M. Warner Losh wrote:
>
> Applications don't fill out struct tm's to compute time_t's. If they
> all did, time_t's definitions wouldn't matter so much. However, many of
> them *KNOW* that it *IS* seconds since 1970 (with leap seconds swizzled
> in, so you can ignore them enti
So many messages, so little time!
M. Warner Losh wrote:
In general, all systems need to be synchronized to human time
because at some point they have to interact with humans.
Right. And human time is synchronized with mean solar time because
we happen to live on the planet Earth. What
On Mon, 22 Dec 2008, Rob Seaman wrote:
>
> No. We have been using mean solar time formally since the 19th
> century, and informally since we woke each morning to light shining through
> the entrance of the cave.
Apparent solar time is not mean solar time. Remember that for a lot of
history
Tony Finch wrote:
On Mon, 22 Dec 2008, Rob Seaman wrote:
No. We have been using mean solar time formally since the 19th
century, and informally since we woke each morning to light shining
through
the entrance of the cave.
Apparent solar time is not mean solar time. Remember that
In message <70692779-0276-4cb0-aab5-43a9c2cf9...@noao.edu>, Rob Seaman writes:
>And others are and have been legally mandated to use mean solar time.
Examples, please ?
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
p...@freebsd.org | TCP/IP since RFC 956
FreeBSD committer
In message <8b194364-41a0-4565-9f5a-4dc99219b...@noao.edu>, Rob Seaman writes:
> Right. And human time is synchronized with mean solar time [...]
What do you really mean by "Synchronized ?"
The civil (and therefore human) time at any spot on the planet, is
offset up to several hours from,
In message: <8b194364-41a0-4565-9f5a-4dc99219b...@noao.edu>
Rob Seaman writes:
: So many messages, so little time!
:
: M. Warner Losh wrote:
:
: > In general, all systems need to be synchronized to human time
: > because at some point they have to interact with humans.
:
:
:
In message:
Rob Seaman writes:
: Tony Finch wrote:
:
: > On Mon, 22 Dec 2008, Rob Seaman wrote:
: >>
: >>No. We have been using mean solar time formally since the 19th
: >> century, and informally since we woke each morning to light shining
: >> through
: >> the entrance of th
Poul-Henning Kamp wrote:
In message <70692779-0276-4cb0-aab5-43a9c2cf9...@noao.edu>, Rob
Seaman writes:
And others are and have been legally mandated to use mean solar time.
Examples, please ?
This issue has come up repeatedly.
Apparently Denmark:
http://www.mail-archive.com/le
The fact that the mean solar rate differs from the SI rate is the
whole enchilada. I have to put the Christmas lights on the tree, but
you could search leapsecs for "secular" and "periodic" to locate my
screed on this topic.
Rob
--
On Dec 22, 2008, at 11:43 AM, M. Warner Losh wrote:
In
In message <174da871-5a3d-4558-8522-eae34ba7e...@noao.edu>, Rob Seaman writes:
>Poul-Henning Kamp wrote:
>>> And others are and have been legally mandated to use mean solar time.
>>
>> Examples, please ?
>
>This issue has come up repeatedly.
>
>Apparently Denmark:
>
> http://www.mail-archive
On Mon, 22 Dec 2008, Rob Seaman wrote:
> The fact that the mean solar rate differs from the SI rate is the whole
> enchilada. I have to put the Christmas lights on the tree, but you could
> search leapsecs for "secular" and "periodic" to locate my screed on this
> topic.
The mean length of year
On Mon, 22 Dec 2008, Poul-Henning Kamp wrote:
>
> The fact that Denmark does not follow its own law on this point
> is a severe blow to your argument.
The thing that amused me about the WP7A update was Britain objecting to
the demise of leap seconds. Our government abolished the Royal Greenwich
Ob
Tony Finch wrote:
> Should we switch to the French Revolutionary Calendar to prevent
> Christmas drifting away further and faster from the winter solstice?
Yes, absolutely! Or even better, the Republic of Terra Calendar:
http://ivan.Harhan.ORG/RT/Calendar/spec.txt
MS
_
Michael Sokolov wrote at 20:12 GMT on Dec 22, 2008:
> Tony Finch wrote:
> > Should we switch to the French Revolutionary Calendar to prevent
> > Christmas drifting away further and faster from the winter solstice?
>
> Yes, absolutely! Or even better, the Republic of Terra Calendar:
>
> h
John Hein wrote:
> By the way, that's a lower case 'c' in 'calendar'.
Yes, thank you for catching my mistake; the correct URL is:
http://ivan.Harhan.ORG/RT/calendar/spec.txt
It was a human mistake on my part, I had typed the URL in from memory
without checking it.
> Let me guess, you
> use ou
You appear to be trying to get a rise out of me. Nothing in my
previous messages were predicated on the de jure or de facto policies
of any governments. That seems to be a facet of your argument. You
asked for an example. I provided.
You also previously chided me to read the archives.
I guess the looming leap second is preying on everybody's mind :-)
By "whole enchilada", I meant the essence of the problem. Do you
disagree?
When the calendar drifts far enough away for some future potentate to
decree that something must be done, what will be done is the insertion
(or o
M. Warner Losh wrote:
We should really consider if it still matters to have things based
on mean solar time at an arbitrary meridian, or if such a coupling
really matters at all. This is the crux of the debate: I think it
is silly, you think it is so obviously critical that we can't find
Poul-Henning Kamp wrote:
Rob Seaman writes:
Right. And human time is synchronized with mean solar time [...]
What do you really mean by "Synchronized ?"
The sun rises, the sun sets. We care about this in innumerable ways.
Other than that, this is the precise issue we have been debating
Finally! All will be happy to know that I've dug back to the
beginning of this morning's crop of messages :-)
Poul-Henning Kamp wrote:
But if you do not make a credible case that something is being
overlooked, nobody is going to waste time on your proposed process
to look for things that
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