On Tue, 1 Jan 2008, Steve Allen wrote:
>
> In the case of TZ, there is no single authority other than, as is
> being posited in the Internet discussions of unique nomenclature for
> zones, IANA.
IANA does not keep any timezone registry, and Internet protocols have for
a long time avoided using tim
On Wed, 2 Jan 2008, Rob Seaman wrote:
>
> Perhaps you could invest five minutes to consider what *will* actually
> happen as DUT1 grows?
They should also worry about the error in the Gregorian calendar.
Tony.
--
f.a.n.finch <[EMAIL PROTECTED]> http://dotat.at/
THAMES DOVER WIGHT PORTLAND PLYMO
On Sat, 9 Feb 2008, Steve Allen wrote:
>
> I think that POSIX time_t should be redefined to be TI, with no leap
> seconds. I think that the leap seconds should be included in the
> zoneinfo files. POSIX already allows that the local time can be
> offset by an arbitrary number of seconds (not just
On Mon, 11 Feb 2008, Joseph S. Myers wrote:
>
> If a system has a timestamp and exports an interpretation of that
> timestamp, and another system stores that interpretation or a second
> timestamp derived from it, and then one system changes its interpretation,
> the timestamps are no longer in syn
On Mon, 11 Feb 2008, Paul J. Ste. Marie wrote:
> Steve Allen wrote:
> >... (BIPM has
> > already indicated openly that if UTC were to abandon leaps they might
> > consider abandoning TAI) ...
>
> I thought TAI/TDT/TDB had all been superseded by so
On Wed, 13 Feb 2008, Rob Seaman wrote:
>
> The "day" is a key concept in our civilization. The "mean solar day" is
> the natural way to implement this. Sundials have nothing to do with the
> mean solar day, but rather the apparent solar day.
How does the mean solar day relate to ephemeris time? Be
On Thu, 14 Feb 2008, Poul-Henning Kamp wrote:
>
> Ahh, but NTP isn't just a mechanism, it mandates UTC timestamps,
> and thus it would be counter to Danish law.
Does Denmark have a national time broadcast service, like MSF or DCF77?
Tony.
--
f.a.n.finch <[EMAIL PROTECTED]> http://dotat.at/
DOV
On Thu, 14 Feb 2008, Steve Allen wrote:
>
> http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19660020453_1966020453.pdf
Thanks for this link. I was previously a bit put off by its length but I
can probably get it into comfortably readable form without killing too
many trees :-)
> For a shorte
On Fri, 15 Feb 2008, Richard B. Langley wrote:
> On Fri, 15 Feb 2008, Tony Finch wrote:
>
> >> For a shorter version see Seidelmann's writeup in
> >> Explanatory Supplement to the Astronomical Almanac,
> >> University Science Books, 1992
> >
> >Not
On Sun, 17 Feb 2008, Magnus Danielson wrote:
>
> It is a very simple law, clearly stateing that throughout all of Denmark shall
> the time be the mean solar time at 15 degree longitude east of Greenwich.
Including the Faeroes and Greenland?
Tony.
--
f.a.n.finch <[EMAIL PROTECTED]> http://dotat
On Tue, 4 Mar 2008, David Malone wrote:
> Easter is quite early this year - early enough that St Patrick's
> day and Good Friday fall in the same week. This is seemingly a
> suprise for the Irish Hoteliers, and is making their life hard:
>
>
> http://www.examiner.ie/irishexaminer/pages/stor
On Thu, 27 Mar 2008, Steve Allen wrote:
>
> Upon further consideration, I'm not sure I agree. For the purposes of
> satellite navigation there is not need for the terrestrial reference
> frame to be tightly tied to the celestial reference frame. Achieving
> accuracy of 1 meter certainly doesn't c
On Fri, 28 Mar 2008, Greg Hennessy wrote:
>
> > although naive math is, well, naive, more code exists that assumes,
> > for example, that midnight it time_t % 86400 == 0 than you want to
> > believe. Changing this is really bad karma.
>
> The current situation is that code like your example does n
On Fri, 28 Mar 2008, Steve Allen wrote:
>
> Part of the beauty of distinguishing broadcast time signals from UTC,
> while continuing both, is that it allows separate issues to be
> addressed separately.
>
> I allow that the broadcast time signals should be leap free, for there
> are many operationa
On Mon, 31 Mar 2008, Rob Seaman wrote:
>
> Like I said, the clocks remained synced through several visits suggesting that
> they received a signal on a regular schedule. They do turn the lights off at
> night, I presume. The underlying clocks are undoubtedly crap, but likely
> can't drift very fa
On Mon, 31 Mar 2008, Clive D.W. Feather wrote:
>
> Um, what buttons on the back? My kitchen RC clock has none such (probably
> because just about all of the UK is in the same time zone).
Mine has buttons to request a radio sync and for manual setting.
http://www.precisionclocks.co.uk/Instructions%
On Wed, 9 Apr 2008, Rob Seaman wrote:
> Yeah, I saw that too, but haven't figured out what symbols he's talking about.
> I just see the familiar text files. Anybody have specific links?
http://www.iers.org/MainDisp.csl?pid=36-1100218
The link is the small white square with the red diagonal line
On Mon, 15 Sep 2008, Rob Seaman wrote:
>
> Hence the prevalence of radians in everyday use :-) The only thing natural
> about the metric system is that humans have ten fingers and the quadrant of
> the Earth something approximating 10 megameters.
The latter was an artificial and deliberate design
On Mon, 15 Sep 2008, Poul-Henning Kamp wrote:
>
> However, following the subsequent mathematical proof that the choice
> of base makes no difference to any kind of math, apart from expense
> of ink and paper to write the numbers, base-2 was left alone until
> somebody much later got the heritical i
On Tue, 28 Oct 2008, Steve Allen wrote:
> On slashdot last month the discussion about the USNO poll on leap
> seconds in broadcast time signals degenerated into one largely about
> daylight time. On contributor pointed out something notable: Civil
> Time has always been the purview of princes.
B
On Mon, 3 Nov 2008, Clive D.W. Feather wrote:
> Tony Finch said:
> >
> > As well as the egregious example of the pre-Julian Roman calendar, I'm
> > amused and disgusted by the anti-Jewish fiddles in the rules for
> > determining Easter to minimise when it coincide
On Sun, 9 Nov 2008, Peter Bunclark wrote:
>
> So a User requirement might be:
> The rythms of life, including the orbits of the earth and the moon,
> the rotation of the earth, and convenient sub-divisions of the rotation
> down to nearly the limit of human perception, shall be expressed in
> a sin
On Mon, 10 Nov 2008, Peter Bunclark wrote:
> On Mon, 10 Nov 2008, Tony Finch wrote:
> >
> > On Sun, 9 Nov 2008, Peter Bunclark wrote:
> > >
> > > So a User requirement might be:
> > > The rythms of life, including the orbits of the earth and the
On Tue, 11 Nov 2008, Poul-Henning Kamp wrote:
>
> There is one requirement you do not seem to even think about, much less
> mention:
>
> The limited human intelligence.
>
> As we saw a couple of years ago, the 400 year leap-year role is slightly
> above the level of complexity humans can deal
On Mon, 10 Nov 2008, Rob Seaman wrote:
> Tony Finch wrote:
>
> > While we are taking a historical view of calendars, it's probably worth
> > observing how past problems similar to the current situation have been
> > resolved. UTC is an observational calendar, and over
On Wed, 12 Nov 2008, Rob Seaman wrote:
> Clive D.W. Feather wrote:
>
> > No, it's because there are no applications where people need to say "what
> > would my GPS receiver had said in 1751?". Whereas people do need to
> > represent older times in (say) POSIX time.
>
> Do they? Example use case fr
On Wed, 12 Nov 2008, Rob Seaman wrote:
>
> However, surely the point of coupling TI with the zoneinfo notion - just for
> the sake of argument - is to simply start distributing TI instead of UTC.
> Then UTC - a flavor of Universal Time, an alias for Greenwich Mean Time (which
> as you say is far fr
On Wed, 12 Nov 2008, Rob Seaman wrote:
>
> Are people really convinced by the argument that badly implemented systems
> should determine policy?
I'm arguing about deployment pragmatics. Note that the systems aren't
badly implemented, they are just following specs based on UT sans leap
seconds.
If
On Wed, 12 Nov 2008, Poul-Henning Kamp wrote:
>
> Savy auction houses deal with such behaviour by not closing the
> auction "while bidding is ongoing", typically implementing a
> 30 second wait after the most recent bid before closing.
> Why eBay doesn't have always been a mystery to me, people wou
On Fri, 12 Dec 2008, Poul-Henning Kamp wrote:
>
> PS: According to Wikipedia, ISO 31-1 defines a day as 86400 seconds,
> anybody here who can verify if this is really the original text ?
ISO 8601-2004 cites ISO 31-1, and specifies several meanings for "day",
one of which is equivalent to 86400 sec
On Fri, 12 Dec 2008, Zefram wrote:
>
> [ISO 8601 is] neutral about whether and when leap seconds may occur:
> that's an application issue. The timezone designators are specifically
> described as being relative to UTC, but it is more consistent with the
> rest of the standard to treat that mention
On Sun, 14 Dec 2008, Zefram wrote:
>
> NOTE These expressions apply to both UTC and non-UTC based time
> scales for time of day.
>
> This seems to be the crucial bit that you missed. It's explicit about
> allowing time scales other than UTC, and doesn't restrict the choice
> of time s
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
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 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 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
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
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
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
On Mon, 22 Dec 2008, Rob Seaman wrote:
>
> 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 omission)
> of an integral number of days in an intercalary event. The mechanism is
> clear, the policy is l
It occurs to me that my proposal for a rational replacement for daylight
saving time also provides an answer to the leap second question.
http://catless.ncl.ac.uk/Risks/25.10.html#subj1
The essence of sunrise time is that we reset our clocks each day to a
fixed time when the sun rises at a benchm
On Tue, 23 Dec 2008, Zefram wrote:
>
> Either of my scenarios still suffers from the problem that the TI-UT
> difference accelerates. These timezone offset changes would be needed
> at decreasing intervals. By the time timezones are jumping by an hour
> every year, one might expect to see politic
On Fri, 26 Dec 2008, Rob Seaman wrote:
>
> Whatever the preferences of the ITU, they will discover that it is
> simply unacceptable to allow local dates to vary secularly from civil
> timekeeping dates.
Civil time *is* a form of local time.
> Only one - standard time based on mean solar time - ha
On Sat, 27 Dec 2008, Rob Seaman wrote:
>
> Rather, a clock can be deposited at any meridian on any planet, set to any
> time, running at any rate. The question is whether a particular choice of
> parameters is useful and sustainable.
Really what it boils down to is a question of how frequently an
On Sat, 27 Dec 2008, M. Warner Losh wrote:
>
> However, the die was cast on this in 1958 when the second was defined in
> terms of atomic behavior. At that point, the game was up, since the
> basic unit of time was decoupled from the day.
The decoupling occurred before then, when the second was d
On Sun, 28 Dec 2008, David Malone wrote:
> > Broad agreement and consensus is the foundation of civil time. The way
> > that leap seconds work clearly does not have enough consensus, in that
> > people still produce software and standards and specifications that
> > are incompatible with leap seco
On Sun, 28 Dec 2008, Poul-Henning Kamp wrote:
>
> In addition to the Olsen database, the book "Calendrical Calculations"
> is probably required.
"Calendrical Calculations" isn't a reliable source for historians in the
way that the Olson database tries to be. CC is a mechanized description of
how c
On Sun, 28 Dec 2008, Poul-Henning Kamp wrote:
>
> In contrast to this, nobody, including you, seem to be willing to
> even hazard a guess what level of presision is required or sufficient
> for the "earth orientation clock".
Well we obviously need to know earth orientation to quite high precision
On Sun, 28 Dec 2008, Rob Seaman wrote:
>
> And I really will spare folks my other screed on civil timekeeping
> having nothing to do with local apparent solar time. Since everybody
> seems to agree on this point, I'm not sure why it keeps coming up.
I don't agree. I think the sun in the sky is wh
On Sun, 28 Dec 2008, Zefram wrote:
>
> The numerical algorithms are correct, as far as I can see, but the
> descriptions of the underlying theory are often muddled, riddled with
> errors and critical omissions. (Count how many different quantities go
> by the name "RD".) Rather importantly for our
On Tue, 30 Dec 2008, M. Warner Losh wrote:
>
> Time used to be strongly coupled to the earth.
Only because it was the most accurate clock we had. It might still be the
most reliable clock we have but our natural tendency to optimisation means
that isn't the most important consideration.
> Actuall
The Guardian soeaks to Peter Whibberley, "a senior research scientist at
the National Physical Laboratory". There's discussion about the future of
leap seconds, and he's against any change in line with the UK's national
policy as we saw in the WP7a summary.
http://www.guardian.co.uk/science/2008/d
On Wed, 31 Dec 2008, Poul-Henning Kamp wrote:
>
> Emperical evidence show that this is indeed the case, and the
> fact that even national time laboratories screw up, underscores
> this fact: http://phk.freebsd.dk/Leap/20051231_HBG/
It's hardly surprising that leap seconds are never handled correct
On Thu, 1 Jan 2009, Rob Seaman wrote:
>
> NTP is proof of concept that automation is possible once the schedule is
> released.
Yes for high stratum clients, but the lowest stratum servers need their
leap second file kept up-to-date, which is a manual task that is often not
performed correctly. Tha
On Wed, 31 Dec 2008, Daniel R. Tobias wrote:
> On 31 Dec 2008 at 8:08, Poul-Henning Kamp wrote:
>
> > Notice the "near": the 0° meridian no longe passes through the
> > transit instrument there.
>
> They moved it? (The meridian, or the transit instrument?)
The meridian moved several times. About
On Thu, 1 Jan 2009, Rob Seaman wrote:
>
> Mean solar time will outlast artificial clocks and the species that
> built them by a factor of something like 5,000,000,000 to 50,000.
Not really, because mean solar time is also artificial and can't exist
without mechanical clocks and telescopes.
Tony.
On Thu, 1 Jan 2009, Rob Seaman wrote:
>
> Once more from the top, mean solar time is just sidereal time offset by a
> little bit to make up for the Earth lapping the Sun once a year. Nowhere does
> humanity appear in the equation, just the Earth and Sun and Stars.
No, since an oscillator without
On Fri, 2 Jan 2009, Rob Seaman wrote:
>
> Mean solar time is highly regular and elegantly simple.
Compared to our clocks it's too irregular.
> Civil timekeeping (even under the ITU proposal) is about the underlying
> diurnal period.
What does atomic time have to do with the position of the Earth
On Fri, 2 Jan 2009, Magnus Danielson wrote:
> b...@po.cwru.edu skrev:
> >
> > That's 303*365+97*366=146097 days for an average of 365.2425 days per year.
>
> Your arthmetic describes solar days, but fails to describe the sidereal days.
No, he's talking about calendar years, as opposed to the conve
On Fri, 2 Jan 2009, Rob Seaman wrote:
>
> So yes, I think the angular momentum of the Earth is more real than the
> observations that might be compiled to generate an estimate for its value.
But the value is an estimate, so if you plug numbers into a model based on
this estimate you are only going
On Mon, 5 Jan 2009, Rob Seaman wrote:
>
> But since just over half the states don't adjoin a timezone boundary with
> another state (I count 27), the statistics are actually more remarkable - more
> than half of U.S. states near a timezone boundary have chosen the awkward
> route of splitting their
On Mon, 5 Jan 2009, Poul-Henning Kamp wrote:
>
> The proper thing for the future is either a "int128_t" 64.64
> fixedpoint time representation or a double ditto.
Do you mean double as in the C type? Which is surely too small - you want
quad-precision FP or perhaps "double double" (paired doubles t
On Mon, 5 Jan 2009, Rob Seaman wrote:
>
> The recent leap second passed (yet again) with no major issues.
Wrong.
Loads of Oracle RAC servers crashed because of a bug triggered by the
clock going backwards.
http://www.merit.edu/mail.archives/nanog/msg13857.html
Many time dissemination systems go
On Mon, 5 Jan 2009, Magnus Danielson wrote:
>
> You could of course to some degree steer the clock on a machine by
> changing the computing load on it, as the tempco of most systems crystal
> is pretty bad. It would kinda work except when it is out of controlrange.
Alternatively you can use clock
On Mon, 5 Jan 2009, M. Warner Losh wrote:
>
> : I wonder why OS vendors don't ship ntpd preconfigured with a leapseconds
> : table that is updated as part of the OS's normal patching process. I hope
> : that would reduce the amount of manual maintenance required for stratum 1
> : servers and increa
On Mon, 5 Jan 2009, Rob Seaman wrote:
>
> Stabilizing civil time with respect to the slowly evolving diurnal rate is
> important. You say so yourself:
>
> http://catless.ncl.ac.uk/Risks/25.50.html#subj1
That post is not entirely serious :-) Perhaps I should post a followup
without my tongue
On Mon, 5 Jan 2009, Brian Garrett wrote:
>
> However, I believe I can safely say that you time lords need not worry
> about what the general public thinks in regard to having clock time
> match the sun's position in the sky, or the "noon becomes midnight"
> scenario. The unwarshed (sic) masses may
On Mon, 5 Jan 2009, Rob Seaman wrote:
>
> Is it too much to ask that an attempt be made to describe how the logistics
> would work?
Exactly the same way that current time zones work. Every so often,
jurisdictions that become dissatisfied with their current timezone offset
or DST arrangements becau
On Tue, 6 Jan 2009, Rob Seaman wrote:
>
> Your April Fool's post on risks may be the most coherent analysis I've
> read on the subject [of DST].
Thanks :-)
> Where I grew up in the U.S. mid-Atlantic states, the most obvious effect of
> DST was to extend the usable hours of daylight for Summer eve
On Tue, 6 Jan 2009, Rob Seaman wrote:
> Tony Finch wrote:
>
> > This is why DST is a sensible solution to the problem of the mismatch
> > between natural human preferences and inflexible timetables based on mean
> > solar time.
>
> I don't think "inflexible
On Tue, 6 Jan 2009, Rob Seaman wrote:
> To return to a previous point, Tony Finch wrote:
>
> > Note that there's no need for global co-ordination. Each country (or
> > county) can change when it is convenient for them. The effect would
> > probably be a shifting of
On Tue, 6 Jan 2009, Adi Stav wrote:
>
> Another suggestion in the same vain: standardize all the time zones of
> the world to two specific dates for starting and ending DST (if they use
> it). Add leap seconds at one of those dates only.
That would require the period of DST to be exactly half the
On Tue, 6 Jan 2009, Adi Stav wrote:
>
> Right. Well, both my memory of the archives and M. Warner Losh's summary
> have uses that need to be aware of UT (actually, I think local sidereal
> time, or ET in some cases, so that have to perform conversions either
> way).
No-one uses ET any more. It has
On Mon, 5 Jan 2009, Rob Seaman wrote:
>
> Alternately, by relying on shifting timezones, there would be no
> underlying stabilized civil timescale permitting commonsense timekeeping
> inferences by humans.
What do you mean by "stabilized" here? Atomic time is the basis of our
most stable time scal
On Wed, 7 Jan 2009, Rob Seaman wrote:
>
> On the other hand, permitting a long delay between events - or rather,
> between scheduling opportunities for events - risks losing the corporate
> knowledge to handle the events properly.
The good thing about timezones is the code to implement them and al
On Wed, 7 Jan 2009, Rob Seaman wrote:
>
> > What common-sense inferences do you have in mind?
>
> Simple utilitarian inferences regarding the world around us.
Such as? I can't think of anything simple enough to count as common sense
which depends on the relation between UT1 and the various local t
On Thu, 8 Jan 2009, Rob Seaman wrote:
>
> The key role that UTC plays in framing the "simple utilitarian inferences
> regarding the world around us" that I mentioned is as a prediction of UT1.
> UT1 itself is only known retroactively.
I still don't know what these inferences are.
Tony.
--
f.anth
On Sun, 15 Feb 2009, Poul-Henning Kamp wrote:
> Daniel R. Tobias writes:
> >
> >Is this stuff all just academic, or does anybody actually have any
> >pre-1972 timestamps (in documents, databases, etc.) for which precise
> >sub-second interpretation is necessary?
>
> I guess only Dennis, Ken or Bria
On Mon, 16 Feb 2009, Steve Allen wrote:
>
> And that means that the POSIX epoch encompasses almost as much
> proleptic fantasy as the use of UTC (or GMT) for the 1601 epoch. The
> observatory at Greenwich wasn't commissioned for another 75 years, not
> until after 3 coronations and a civil war. I
On Tue, 17 Feb 2009, Gerard Ashton wrote:
>
>Concatenate the "epoch" time at the time this ID value is being
>generated ; the "epoch" time is the number of seconds elapsed since
>00:00:00 Coordinated Universal Time (UTC) January 01,
>1970 (not counting leap seconds)
>
> 2. It has al
On Tue, 17 Feb 2009, Joseph M Gwinn wrote:
>
> > The navigators who used marine chonometers knew perfectly well that
> > those chronometers did not keep the "right" time as measured by clocks
> > on land being reset by telescopes. Instead they knew that if their
> > chronmeters were treated well t
On Thu, 10 Sep 2009, Poul-Henning Kamp wrote:
>
> Obviously, Neither ITU nor BIPM has any control over what "Human
> Time" is or how it works. National and federal lawmakers decide
> that, often illadvisedly, and occationally very stupidly. China,
> as I recall, is one single timezone, and some
On Thu, 10 Sep 2009, Steve Allen wrote:
>
> I believe that this can only happen if one of the member delegations
> submits a document detailing such a proposal. It would seem most
> likely for it to come from a nation where mean solar time is the
> current legal standard (Denmark? UK?).
The UK do
On Thu, 10 Sep 2009, Rob Seaman wrote:
>
> It is precisely the fact of a international civil timescale that makes the
> timezone system work.
Yes.
> In return, the many timezones and numerous special cases represent
> constraints on the common underlying standard to better track mean solar
> time
On Fri, 11 Sep 2009, Steve Allen wrote:
> On 2009 Sep 10, at 07:11, Tony Finch wrote:
> > The UK doesn't acknowledge any difference between GMT and UTC.
>
> But they are aware of it
I meant the UK government. See for example the millennial fuss about
putting some atomic clo
http://www.wired.com/wiredscience/2010/02/quantum-logic-atomic-clock
The article is misleading in several ways, most particularly about it
being "100 000 times more precise". What they mean is that the frequency
standard (a 1.1PHz UV laser) that is steered by the paired aluminium and
magnesium ion
On Mon, 1 Mar 2010, Poul-Henning Kamp wrote:
> Rob Seaman writes:
> >
> > GPS is being built into critical infrastructure, [...]
>
> Ohh, I don't disagree with that being patently stupid, without a
> good backup system.
I don't need to tell Poul-Henning about LORAN-C, which AIUI is much harder
to
Is there a generic term for timescales like POSIX time_t and NTP that
count seconds (or some other interval) since an epoch without taking
leap seconds into account?
Tony.
--
f.anthony.n.finchhttp://dotat.at/
GERMAN BIGHT HUMBER: SOUTHWEST 5 TO 7. MODERATE OR ROUGH. SQUALLY SHOWERS.
MODERATE
On Tue, 9 Mar 2010, Steve Allen wrote:
> On Tue 2010-03-09T17:07:01 +0000, Tony Finch hath writ:
> >
> > Is there a generic term for timescales like POSIX time_t and NTP that
> > count seconds (or some other interval) since an epoch without taking
> > leap seconds into a
On 11 Mar 2010, at 02:20, "M. Warner Losh" wrote:
But maybe we need to borrow from my college days in physics class
and call it an "idealized time count" or something like that to show
that it is a polite fiction that makes the math easier and mostly
right most of the time...
Consider a
On Thu, 5 Aug 2010, Steve Allen wrote:
> On Thu 2010-08-05T14:55:25 -0600, M. Warner Losh hath writ:
> > in the UK there's not a clear distinction between GMT and UTC and
> > often (but not always?) the terms are used interchangeably.
>
> Listen to the BBC. Many of the readers will announce that i
On Fri, 6 Aug 2010, Poul-Henning Kamp wrote:
>
> For starters, the actual change happend in 1958 when the clock
> running the free-of-charge "Fr?kken Klokken" telephone service
> was adjusted to UTC.
Er, no. 1958 was when TAI started. The predecessor of UTC started in 1961.
(Which is not to disag
On Mon, 9 Aug 2010, Poul-Henning Kamp wrote:
>
> EU directive says DST starts at 01:00Z
But the EU directive is not consistent about whether Z is UTC or UT so it
cannot be interpreted to require UTC.
Tony.
--
f.anthony.n.finchhttp://dotat.at/
HUMBER THAMES DOVER WIGHT: SOUTHERLY OR SOUTHWEST
On Wed, 11 Aug 2010, ashtongj wrote:
> If dropping leap seconds is ultimately approved, we will need at least two
> names for the new time scale.
Alternatively, name the successor to UTC "TI" and if you want proleptic TI
call it "proleptic TI".
Tony.
--
f.anthony.n.finchhttp://dotat.at/
IRI
On 12 Aug 2010, at 21:25, Michael Deckers wrote:
>
> I fear that the matter is less simple. The proposal keeps the
> name UTC for the newly defined timescale. (And unfortunately,
> there is precedent with essential changes in definitions of well
> established time scales: GMT.)
AIUI the
On Fri, 27 Aug 2010, Ian Batten wrote:
>
> Although unrelated, it would also open up the whole "moving the UK to WET" can
> of worms, which has become distinctly toxic because of the implications for
> Scotland.
The UK is currently on WET (same as Portugal). There is a small but noisy
lobby that w
On Wed, 1 Sep 2010, Daniel R. Tobias wrote:
>
> If the time zone boundaries were drawn with any sort of logic with
> respect to keeping the times close to the natural solar time in each
> location, then France and Spain would join the UK and Portugal in
> WET, rather than the UK shifting the other
On Thu, 2 Sep 2010, Ian Batten wrote:
>
> It'll be interesting in the UK
Yes.
> * There's no doubt that UK legal time is GMT, Interpretation Act 1978, S.9
>
> * There's no doubt that whatever GMT is, it's solar, and there's no doubt
> that whatever UTC is, it isn't solar and would be even less s
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