On Wed 2011/02/16 01:34:57 -, Tony Finch wrote
in a message to: Leap Second Discussion List leapsecs@leapsecond.com
I have been saying that, as a reason for changing UTC today, it is
a specious argument that should be rejected.
Yes.
Agreement!
It's also a bogus argument for keeping leap
On 15 Feb 2011, at 05:46, Rob Seaman wrote:
Combining these improved predictions with prudently relaxed DUT1 constraints
should permit extending leap second scheduling to several years.
These steps can be taken today with no tedious international negotiations.
The UK's standard time
In message 8e992e8a-cc16-44ec-a73e-e569d9395...@batten.eu.org, Ian Batten wri
tes:
The UK's standard time broadcast, which is funded by the government,
contains DUT1 in a format which doesn't permit |DUT1|0.9.Whatever
people argue (rightly) about the de facto legal time in the UK being
UTC,
Poul-Henning Kamp said:
The UK's standard time broadcast, which is funded by the government,
contains DUT1 in a format which doesn't permit |DUT1|0.9.Whatever
people argue (rightly) about the de facto legal time in the UK being
UTC, the de jure legal time is GMT which is taken to be UT1.
In message 20110215100536.gd78...@davros.org, Clive D.W. Feather writes:
Poul-Henning Kamp said:
The UK's standard time broadcast, which is funded by the government,
contains DUT1 in a format which doesn't permit |DUT1|0.9.Whatever
people argue (rightly) about the de facto legal time in
Poul-Henning Kamp said:
Mean Solar Time = UT1 = GMT:
So everybody using NTP and deriving GMT withut applying DUT are in
breach of the law ?
They're simply getting it wrong. The law doesn't require the use of GMT
for everything; it just defines what legal time is.
If it came to a lawsuit over
On Tue, 15 Feb 2011, Mark Calabretta wrote:
The quadratic calamity is one of the few concrete arguments given by
the proponents of dropping leap seconds (viz the GPS World article).
I had another look at the article, and it doesn't use the quadratic
increase DUT1 as an argument against UTC.
On Tue, 15 Feb 2011, Paul Sheer wrote:
Have you looked at the Olson source?
Yes.
In any case, whatever solution ye'all come up with should not
merely be In Principle. It should come as a patch on some real code.
No patches are needed.
If leap seconds are abolished then POSIX's model of
Tony Finch d...@dotat.at :
[...]
There is already code to handle leap seconds like timezones, but it is
incompatible with POSIX and large amounts of other code and with NTP and
other time broadcast systems.
Of course you are exactly right.
Now, consider an application that wants to
On Mon, 14 Feb 2011, Mark Calabretta wrote:
On Fri 2011/02/11 15:42:41 -, Tony Finch wrote
See for example
http://six.pairlist.net/pipermail/leapsecs/2011-January/002124.html
where Rob Seaman wrote Civil timekeeping is cumulative. Tiny mistakes
posing the problem will result in large
Tony Finch wrote:
Rob frequently argues that we can't use a pure atomic timescale as the basis
of civil time because of the quadratically increasing offset betwee UT1 and
TAI.
Well no, I don't think I've ever made such an argument. It is a question of
rates, not offsets. And the two
Tony Finch wrote:
Furthermore using timezones to keep civil time in sync with
the sun leads to simpler software and it will work for over
ten thousand years.
No. Breaking timezones on top of breaking UTC with the
apparent motivation of allowing TAI to be suppressed is
bad on top of
On Tue 2011-02-15T02:07:59 +0200, Paul Sheer hath writ:
In any case, whatever solution ye'all come up with should not
merely be In Principle. It should come as a patch on some real code.
Which part of this is not already implemented by the code when
it uses the right zoneinfo files?
To be
On Mon 2011/02/14 18:00:02 -, Tony Finch wrote
in a message to: Leap Second Discussion List leapsecs@leapsecond.com
Rob frequently argues that we can't use a pure atomic timescale as the
basis of civil time because of the quadratically increasing offset between
UT1 and TAI. You yourself made
On Mon, 2011-02-14 at 16:23 -0800, Steve Allen wrote:
Which part of this is not already implemented by the code when
it uses the right zoneinfo files?
1. let say we want a future where timezones are adjusted by 30 minutes
whenever the sun starts rising too late. Write this into the Olson
What's the point?
Two links to refresh the discussion:
http://www.springerlink.com/content/g216411573882755/
http://maia.usno.navy.mil/eopcppp/eopcppp.html
Paul Sheer wrote:
I think what you will find is that there is no technical difference between
moving leap seconds into
Mark Calabretta said:
The speculation on the list is that in the absence of a central
authority, local governments will act as their people request when it is
staying dark too late and parents can't get their kids to bed with the
sun still shining, or have to drive to work in the dark too
On Fri, 11 Feb 2011, Mark Calabretta wrote:
On Thu 2011/02/10 10:43:40 -, Tony Finch wrote
Also, the quadratic catastrophe argument is usually used in support of
UTC.
Really? Can you provide references for that.
See for example
Ian Batten said:
And people routinely live in places where solar time is several hours adrift
from civil time --- Brest, France for example is four degrees west of
Greenwich, yet in the summer is on UTC+2 --- so at noon civil time it is 0945
solar time.
Parts of (mainland) Spain are even
On Feb 11, 2011, at 8:42 AM, Tony Finch wrote:
See for example
http://six.pairlist.net/pipermail/leapsecs/2011-January/002124.html
where Rob Seaman wrote Civil timekeeping is cumulative. Tiny mistakes
posing the problem will result in large and growing permanent errors.
Great to see folks
On Thu, 10 Feb 2011, Mark Calabretta wrote:
Leaping timezones would be tenable if they all leapt at the same
time. However, I think we agree that that won't happen.
They leap about all the time at arbitrary times, so I wonder why you
think that isn't tenable.
Currently the main chaotic
On Thu, 10 Feb 2011, Mark Calabretta wrote:
If we're seriously expected to accept the quadratic catastrophy
argument for immediately changing UTC
Also, the quadratic catastrophe argument is usually used in support of
UTC. It is argued that a very small and slowly increasing rate difference
On 10 Feb 11, at 0122, Mark Calabretta wrote:
On Wed 2011/02/09 11:44:14 PDT, Warner Losh wrote
in a message to: leapsecs@leapsecond.com
The speculation on the list is that in the absence of a central
authority, local governments will act as their people request when it is
staying
It's been a while... Can you remind me why we will need to continue
to pretend that there are 86400 SI seconds in a day, past the time
when there are actually 86401 (or more)?
Why is because there is a semi-infinite number of existing
lines of code, right now in use, that calculate the
On Feb 10, 2011, at 5:39 PM, Warner Losh wrote:
Without a plan, people will keep doing what they are doing now. Today's code
might not be around in 10k years, but if people don't come up with a plan,
then code written 1k or 5k years from now will still have the same problems.
I think the
In message 20110209025648.gb5...@ucolick.org, Steve Allen writes:
Further evidence of this is that UN registers all internation
treaties its member states have entered into, in accordance with
the UN charters article 102, and you can see all of these treaties
at http://treaties.un.org
In
In message 0ea57b08-af7c-4bbe-8a56-b1376e873...@batten.eu.org, Ian Batten wri
tes:
Sovereign states have some degree of control over civil time; [...]
Although it's not obvious to me that in the UK, at least, they have any
practical authority over time. The Weights and Measures Act 1985
On Tue, 8 Feb 2011, Warner Losh wrote:
On 02/08/2011 14:39, Rob Seaman wrote:
C) As pointed out on numerous occasions in the past, these kaleidoscopic
timezones would accelerate quadratically just like leap seconds.
This problem isn't solved by this method either. True.
Except that
On Tue, 8 Feb 2011, Rob Seaman wrote:
B) Detailed expert knowledge would become necessary to answer even
simple questions of comparing both clock intervals and Earth
orientation questions either in a single place or across epochs and
locations.
We have that today.
We have a soupçon
In message ae1ee06f-17e5-46e2-abc2-c0700cb1a...@noao.edu, Rob Seaman writes:
Clive D.W. Feather wrote:
I reserve the right to disagree. The point is that dumb is what
the rubber timezone folks say - and rubber timezones are an order
of magnitude more dumb than either rubber seconds or
Tony Finch wrote:
Warner Losh wrote:
Rob Seaman wrote:
C) As pointed out on numerous occasions in the past, these kaleidoscopic
timezones would accelerate quadratically just like leap seconds.
This problem isn't solved by this method either. True.
Except that timezone adjustments
On 02/09/2011 09:05, Rob Seaman wrote:
Tony Finch wrote:
Warner Losh wrote:
Rob Seaman wrote:
C) As pointed out on numerous occasions in the past, these kaleidoscopic
timezones would accelerate quadratically just like leap seconds.
This problem isn't solved by this method either. True.
On Wed, 9 Feb 2011, Rob Seaman wrote:
PHK's position is that hundreds of local governments (that he appears to
consider beneath contempt) would have to act separately or severally
during each adjustment.
Right. Just as they do at present for political reasons.
Even if one-a-day is
On Wed, 2011-02-09 at 09:49 -0700, Warner Losh wrote:
It is a lot easier to adjust by an hour for local time than it is to
have a leap second every month, or more often. Thus Tony is right: the
zoneinfo files adjusting local time via timezone shifts mandated by
local government would
On 9 Feb 2011, at 18:44, Warner Losh wrote:
On 02/09/2011 10:48, Rob Seaman wrote:
The idea that's been put forth is that the transition would be
made all at once. Eastern Time zone would go from TI-5 to TI-4,
most likely by failing to fallback one year in the fall.
Exercise for the
In message 6d097a07-04ec-4ace-ad99-4c647ab22...@noao.edu, Rob Seaman writes:
In context my statement was:
By comparison, a leap second is introduced by a central
authority [...]
What authority would that be, and what powers would it have ?
Remember: it's called a recommendation for a
Poul-Henning Kamp wrote:
What authority would that be, and what powers would it have ?
Per SERVICE INTERNATIONAL DE LA ROTATION TERRESTRE ET DES SYSTEMES DE
REFERENCE, we know that:
NO positive leap second will be introduced at the end of June 2011.
I don't need to remind you, that
In message e97e8012-cc6f-4948-b291-a82868873...@noao.edu, Rob Seaman writes:
Poul-Henning Kamp wrote:
What authority would that be, and what powers would it have ?
Per SERVICE INTERNATIONAL DE LA ROTATION TERRESTRE ET DES SYSTEMES DE
REFERENCE, we know that:
NO positive leap second
On Wed 2011/02/09 10:59:39 -, Tony Finch wrote
in a message to: Leap Second Discussion List leapsecs@leapsecond.com
Except that timezone adjustments continue to work much further into the
future than leap seconds.
If we're seriously expected to accept the quadratic catastrophy
argument for
On Wed 2011/02/09 11:44:14 PDT, Warner Losh wrote
in a message to: leapsecs@leapsecond.com
The speculation on the list is that in the absence of a central
authority, local governments will act as their people request when it is
staying dark too late and parents can't get their kids to bed with
Tony Finch wrote:
the whole point of universal time is that it's the default timscale
for civil use and only specialists should need anything else.
Seeking consensus, I said:
Stephen should add this to the consensus building list.
Tony said:
Does that mean that you agree that its very
In message c222a54a-321e-4a5f-ad7a-efb12a4fd...@noao.edu, Rob Seaman writes:
Phrases like tight coupling are misleading. The ITU position
has only ever been to remove *all* coupling. On this list we have
often discussed various ways to relax the current constraints. It
is the ITU who have been
On Tue, 8 Feb 2011, Rob Seaman wrote:
I'd say that history is pretty quiet on timekeeping issues in general.
I think very highly of Dava Sobel's Longitude, but one book does not a
library make.
There's also Saving the Daylight by David Prerau. (The title has varied
a bit.)
Also Calendrical
I said:
Civil timekeeping is a worldwide system.
Poul-Henning Kamp wrote:
No it is not.
It is remarkable how the most aggressive responses to my posts are when I
mention system engineering or best practices or otherwise suggest that this
is fundamentally an exercise in proper system
Sovereign states have some degree of control over civil time; the
remaining control is
in the control of individuals, either through personal whims or
voluntary collective
action. The IAU, ITU, BIPM, ISO, and all the rest do not have control
over civil timekeeping
because the weights and
On Tue, 8 Feb 2011, Rob Seaman wrote:
UTC is not civil time anywhere,
I understand that you wish to assert that local time == civil time.
But you also assert that computer networks worldwide must be
synchronized. Is this latter somehow not a civil function?
Civil usually relates to a
On 02/08/2011 07:55, Rob Seaman wrote:
Regarding your current question, I would personally assert:
Coupling civil timekeeping to Earth rotation is a necessary feature.
I suspect some others here might not be willing (yet) to promote this to
consensus :-)
Phrases like tight coupling
On Tue 2011-02-08T13:14:27 -0700, Warner Losh hath writ:
I'd be willing to agree that Coupling of Civil time to the earth is
required. Coupling of the successor to UTC isn't required, or at least
there's not consensus that it is required.
The broadcast time signals should be as uniform as is
On 02/08/2011 13:29, Steve Allen wrote:
On Tue 2011-02-08T13:14:27 -0700, Warner Losh hath writ:
I'd be willing to agree that Coupling of Civil time to the earth is
required. Coupling of the successor to UTC isn't required, or at least
there's not consensus that it is required.
The broadcast
Warner Losh wrote:
The current ITU proposal would have the effect of moving the coupling of the
Earth's rotation from the time that is broadcast (now called UTC) to the
timezones that local governments promulgate.
This would be chaos for anyone needing to compare timestamps in different
Poul-Henning Kamp wrote:
Sometimes it is civil, sometimes it is military, most of the time it is
corporate.
We have frequently debated vocabulary here. This is why I suggested a glossary
would be a good idea.
Civil timekeeping has often been taken to mean something like the common
On 2011-02-08 16:29, Poul-Henning Kamp wrote, answering
Rob Seaman:
Civil timekeeping is a worldwide system.
No it is not.
UTC is a worldwide coorporation or worldwide coordination if you
will.
There is no international entity which can mandate what civil time
must be in any
In message 20110208202941.gg1...@ucolick.org, Steve Allen writes:
Most governments of the world are signatories to agreements which
state that Universal Time is a subdivision of the mean solar day which
ultimately produces the calendar.
What argrements are you thinking of ?
And is the averaging
Warner Losh wrote:
How would it be any different than today? Every few hundred years, the
government moves the time zone. Heck, they do that now every few years
anyway. Each government would be able to move it as they saw fit, or follow
other government's leads. If the US move and
On 02/08/2011 14:39, Rob Seaman wrote:
Warner Losh wrote:
How would it be any different than today? Every few hundred years, the
government moves the time zone. Heck, they do that now every few years anyway.
Each government would be able to move it as they saw fit, or follow other
Warner Losh replies:
A) It would be taking what is currently a doubly indirect pointer and
removing the layer in the middle. Dereferencing (converting to UTC) would
no longer return a timescale stationary with respect to the synodic day.
I don't see why it wouldn't. If you really need
On 02/08/2011 16:30, Rob Seaman wrote:
Even the olson database won't give you all the answers, but it will give you
many of them.
But you guys continue to reject Steve Allen's zoneinfo option...which
represents a system layered on a relatively static timezone DB. Punting to
local
On 02/08/2011 17:19, Steve Allen wrote:
On Tue 2011-02-08T17:03:31 -0700, Warner Losh hath writ:
NTP also does everything in UTC time
No, NTP does not use UTC per se.
The existing implementations make that specification misleading.
Rather, NTP uses the internationally approved broadcast time
On Tue 2011-02-08T21:56:35 +, Poul-Henning Kamp hath writ:
If you read the minutes of the conference, you will find that at
best it amounts to a joint proposal on terms of reference for
geographical coordinates, and that serveral questions of timekeeping
specifically a declared out of
On 8 Feb 2011, at 17:05, Gerard Ashton wrote:
Sovereign states have some degree of control over civil time; the remaining
control is
in the control of individuals, either through personal whims or voluntary
collective
action. The IAU, ITU, BIPM, ISO, and all the rest do not have control
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