> On Jan 1, 2019, at 1:03 PM, Brooks Harris wrote:
>
> Back in the days of analog TV (which is still used in some parts of the
> world) the broadcast TV signal was one of the most stable time sources
> around. This was necessary because the display of the signal on a CRT TV set
> depended cr
> On Aug 11, 2018, at 9:27 AM, Rob Seaman wrote:
>
> Whatever the outcome this year, the writing is on the wall.
This misses the point. Everything that the U.S. Government does requires the
annual support of Congress. Everything except entitlements are subject to
annual appropriations. And
I don’t disagree with your interpretation of UTC, but there’s no error in the
announcement. The leap second is added at 23:59:59. While the leap second
itself is 23:59:60, it’s during the interval 23:59:59 when the logic is changed
for what the next second should be labelled.
- Jonathan
gt; On May 20, 2015, at 1:51 AM, Poul-Henning Kamp wrote:
>
>
> In message <32c69001-db69-46c4-905f-d994b017b...@tcs.wap.org>, "Jonathan E.
> Hardis" writes:
>
>> That box of Wheaties that is labelled 'Net Weight 10 oz' would
>> corr
> On May 19, 2015, at 3:02 PM, Richard Clark wrote:
>
> It was around the late 1600's that it started becomming possible (and
> necessary) to decouple weight and mass.
The sound you hear is the sound of chalk screeching on the blackboard.
“Weight” is an ambiguous term that can either mean “for
On Jan 16, 2012, at 3:20 PM, Poul-Henning Kamp wrote:
It would require a lot of editorial work in a LOT of international
documents...
While they're at it, they can replace kilobyte with kibibyte (kB ->
KiB), megabyte with mebibyte (MB -> MiB), gigabyte with gibibyte (GB -
> GiB), etc.
A
On Aug 18, 2011, at 8:50 AM, mike cook wrote:
Lawyers like that stuff.
And judges, who tend to have overloaded calendars of important
matters, like the motto: "de minimis non curat lex."
- Jonathan
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A note for you horologists in the U.S
Beginning in about a month (approx. July 14), the electric power
industry will stop making "Time Error Corrections" on the U.S. power
grid. For those timekeeping devices that rely on 60 Hz power as their
frequency reference, based on past experienc
On Apr 14, 2011, at 6:08 AM, Zefram wrote:
http://www.leapsecond.com/pages/Junghans/
That page appears to describe exactly the kind of poor synchronisation
behaviour by which I was so appalled.
Does anyone really care about exceeding 0.15 s accuracy on a wrist
watch?
Speaking for myself
On Jan 31, 2011, at 11:59 AM, Finkleman, Dave wrote:
BTW, the Moslem day begins at observable moon rise, which is different
than sunset. Orthodox observers in several religions (Judiasm,
Islam,
and others) are very concerned about precise definitions of these
events
and timing of prayer
On Jan 1, 2011, at 9:52 AM, Daniel R. Tobias wrote:
The network techies, however, do need to concern themselves with
being precisely synced to whatever time standard the Times Square
people use; it would be embarrassing if the ball dropped a second
early or late compared to their countdown
On Jan 1, 2011, at 12:05 AM, Daniel R. Tobias wrote:
I just watched the ball drop in Times Square (on TV, not in person!),
and noticed that my watch (auto-synced daily via radio signal) was
about 15 seconds fast compared to the countdown clock used by the
Times Square people and the TV network.
On Dec 30, 2010, at 7:41 PM, Rob Seaman wrote:
It is *hasty* to force a decision when the current definition of UTC
is viable for centuries.
This is not being responsive. There are those who believe that the
current definition of UTC isn't viable TODAY.
As someone else points out, it is
On Dec 30, 2010, at 7:49 PM, Greg Hennessy wrote:
To repeat myself, the punch line is this: NO ONE is advocating a
perpetual drift apart between atomic time and "universal" time
(sundial time).
What do you base this on, since I think the ITU proposal is exactly
that?
The proposal is to
On Dec 30, 2010, at 4:55 PM, Finkleman, Dave wrote:
[Bob Nelson] has communicated with OSD and my employer castigating
my campaign for
consensus that considers the consequences. His communication is all
emotion and no substance. He conjectures great damage to national
security and inevitabl
On Dec 24, 2010, at 10:51 AM, Rob Seaman wrote:
On Dec 23, 2010, at 5:45 PM, Jonathan E. Hardis wrote:
WHERE under U.S. jurisdiction is UTC (no offset) the legal, civil
time?
Cleaner answers still await, however.
Commercial aircraft in flight?
Close enough. U.S. Flag vessels, and I
On Dec 23, 2010, at 8:04 PM, Rob Seaman wrote:
On Dec 23, 2010, at 5:45 PM, Jonathan E. Hardis wrote:
WHERE under U.S. jurisdiction is UTC (no offset) the legal, civil
time?
There's the ISS, but on the other hand does "jurisdiction" mean much
until it has been chal
In message <66237b3a-3953-43ff-86d6-9ae1befa5...@tcs.wap.org>,
"Jonathan E. Har
dis" writes:
You might want to rephrase that as a trivia question: WHERE under
U.S. jurisdiction is UTC (no offset) the legal, civil time?
On Dec 23, 2010, at 4:22 PM, Brian Garrett wrote:
Also US researc
On Dec 22, 2010, at 3:36 PM, Steve Allen wrote:
In constrast, WWV and WWVB do transmit UTC, but nowhere in any U.S.
jurisdiction is that the legal civil time.
You might want to rephrase that as a trivia question: WHERE under
U.S. jurisdiction is UTC (no offset) the legal, civil time?
On Dec 11, 2010, at 12:36 PM, Ian Batten wrote:
Well, except for Active Directory, which sets an upper bound of five
minutes on the maximum error. In practice, an AD deployment in
which clocks were allowed to drift apart by minutes would behave
very badly, so the typical target is less th
On Nov 3, 2010, at 6:53 PM, Ian Batten wrote:
...otherwise UTC(GPS) is fine...
There is no such thing as UTC(GPS).
The GPS signal provides the offset that allows the receiver to compute
UTC(USNO). It can also be used to disseminate UTC estimates of other
national laboratories, but they
On Nov 2, 2010, at 11:05 AM, Rob Seaman wrote:
On Nov 2, 2010, at 7:06 AM, Clive D.W. Feather wrote:
The reason I haven't been involved in this thread up to now is that
I spent the last week in a place where apparent solar time and
official clock time were about 7800 seconds apart. It was
On Oct 24, 2010, at 3:29 AM, Rob Seaman wrote:
But this isn't the discussion we've been having for ten years - and
we aren't the ones to convince. On this list we have speculated
widely on possibilities of all sorts, but the entire time a
relentless and inflexible and closed-door campaign
On Oct 24, 2010, at 4:35 PM, Daniel R. Tobias wrote:
On 24 Oct 2010 at 18:12, Poul-Henning Kamp wrote:
Medicine production is another case: In continuous production
setups, all materials have to be traceable to with second
granualirity
Why is the precise second something was manufactured
On Oct 23, 2010, at 1:48 PM, Hal Murray wrote:
How many of these systems CURRENTLY properly handle leap seconds?
How
many of these cell phones and space systems and digital devices
"buried
beneath Antarctic ice" CURRENTLY are built to a specification that a
minute can contain either 59,
On Oct 22, 2010, at 11:14 PM, Rob Seaman wrote:
... Clocks appear in numerous places in the workflow. It is no
simple feat to coordinate all these clocks with vintages ranging
over the last quarter century. GPS? Phones? Web apps?
Data start at a mountaintop telescope, but flow downhil
On Oct 22, 2010, at 1:16 PM, Rob Seaman wrote:
It will, for instance, cost astronomers many millions of dollars
simply to restore current functionality to thousands of
interoperating systems.
Oh ... come, come.
How do these "thousands of interoperable systems" currently get the
time?
On Sep 23, 2010, at 9:55 PM, Steve Allen wrote:
On Thu 2010-09-23T20:45:45 -0400, Jonathan E. Hardis hath writ:
As the link makes clear, WAAS is funded by the FAA "for aircraft,"
not
"for surveying."
As the folks who are trying to abandon leap seconds seem to think,
ju
On Sep 23, 2010, at 3:35 PM, Steve Allen wrote:
for robustness against the ionosphere (mostly for surveying) see WAAS
http://en.wikipedia.org/wiki/Wide_Area_Augmentation_System
As the link makes clear, WAAS is funded by the FAA "for aircraft," not
"for surveying."
Aircraft and surveying h
On Aug 27, 2010, at 12:49 PM, Steve Allen wrote:
At the open meeting of US SG7 last week the participants responded
that GPS time was a "pseudo time scale".
Since you opened with this statement some might read it as having
significance to this discussion. It does not, really.
Many regar
On Aug 13, 2010, at 5:00 AM, p...@2038bug.com wrote:
All this talk of GMT/UTC/Legislature makes me ask how the world
currently syncs their time.
http://www.bipm.org/en/scientific/tai/tai.html
The best method is Two-Way Satellite Time and Frequency Transfer
(TWSTFT), utilized by those labo
On Thu, 5 Aug 2010 13:45:24 -0700 Steve Allen
wrote:
What countries do you think are using UT1 (or another time scale with an
astronomical basis) for their legal time, and which would therefore
drift away from those using UTC?
Notably, Denmark.
Well, then I would expect that the U.S. Congres
On Thu, 5 Aug 2010 13:45:24 -0700
Steve Allen wrote:
On Thu 2010-08-05T16:29:17 -0400, ashtongj hath writ:
On 2010-08-05 3:17 PM, Jonathan E. Hardis wrote:
The 15th Conference Generale des Poids et Mesures (the formal body
formed by the Treaty of the Meter) "strongly endorsed" th
On Thu, 05 Aug 2010 13:54:49 -0400
ashtongj wrote:
If the leap second is dropped, the
change will become perceptible to ordinary voters,
especially when there are several seconds difference in
the seconds field of legal time in the U.S. compared to
some other countries.
The 15th Conférence
http://www.wired.com/wiredscience/2010/02/quantum-logic-atomic-clock
...
There are some other misleading statements in that article.
There's no need to change the definition of the second because the latest
frequency standard is based on a different quantum transition. Magnesium,
mercury, and y
It is also remarkable that about one-fourth (12) of the U.S. states
are bisected by timezones
14 states:
Alaska, Idaho, Oregon, Nevada, North Dakota, South Dakota, Nebraska,
Kansas, Texas, Michigan, Indiana, Kentucky, Tennessee, and Florida
I would take this as evidence that people actually
Sprint's cellular network has still NOT got it right,after four
days. My cell phone, whose time display used to change right on the
tick of the UTC second, is now one second slow. Sprint is a CDMA
network, which as far as I know runs on GPS time, so it would appear
that some code indicating t
I've put the attachment online as I should have in the first place:
http://iraf.noao.edu/~seaman/images/HowLongIsADay.pdf
Nice.
Thanks!
- Jonathan
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While I can't speak for the USNO's sister-institution, I do
remember the paper referenced below. It was presented at a PTTI
meeting by someone who at that time was an employee of NIST and this
must be why they include it in their reprint library. I am quite
sure that it does not now represent
we also learn that "Universal Time (UT) is the general designation
of time scales based on the rotation of the Earth."
Then it's not very "Universal," now is it?
You can still consider it an oxymoron, if you'd like.
- Jonathan
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In short, much of the dysfunctionality of the current scenario is a
result of NOBODY being in charge of UTC. To say that the ITU-R is
actually the owner of UTC is somewhat of a fiction, both in history
and current practice.
Please rest assured that the same group of experts show up to both
the
The NIST web pages also make the wikipedia-cited claim that the ITU
chose the apellation "UTC".
http://tf.nist.gov/general/misc.htm#Anchor-14550
I can find no evidence to support this, and much evidence to refute
it. Perhaps the evidence is buried in one of the private documents
shelved in Gene
Correct. However, the die was cast on this in 1958 when the second
was defined in terms of atomic behavior.
It was 1967.
At that point, the game was up, since the basic unit of time was
decoupled from the day. We transitioned from having rubber seconds,
to having rubber days. I suppose we
For the leap second on WWV/WWVH you will "hear" two omitted ticks
instead of one at the 59th/60th seconds. Feel free to check out
www.time.gov for the leap second also - it should show the 23:59:60.
...but only if you push the tiny "UTC" button.
If you do the obvious thing and click on the gr
The POSIX and FIPS-151-2 requirement is that you use UTC (with 86400
seconds per day), they doesn't say how good you have to be at it.
Hey guys, I hate to spoil all of your fun, but FIPS 151-2 was
WITHDRAWN eight years ago.
http://frwebgate.access.gpo.gov/cgi-bin/getdoc.cgi?dbname=2000_regist
In message <[EMAIL PROTECTED]>, Rob Seaman writes:
I thought USA went out of their way some years back, to make it
clear that the relevant secretary (of commerce ?) decided what
US timekeeping was and that it certainly had nothing to do with GMT ?
Or was that laying the ground for US unlateral a
Does anybody have any thoughts on the effect(s) of the previous and/or
upcoming leap seconds on NTP (v2, v3, and/or v4)? For example, on
protocols that implement sub-second timers (such as BFD)? TCP? IGMPv3?
Please see
http://www.eecis.udel.edu/~ntp/ntpfaq/NTP-s-algo.htm#AEN2432 ("What
Happ
I'd be interested to know if CDMA cellular networks were disrupted more than
others. CDMA is the only cellular telephony protocol that requires perfect
sync between *all* parts of the network including handsets.
The empirical evidence is that such an event only affects the ability
of CDMA netwo
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