Hi,
On 1/1/19 3:15 PM, Daniel R. Tobias wrote:
> A lot of Americans synchronize their new year celebrations to the
> drop of the ball in Times Square as seen on TV, which means they
> celebrate a few seconds late because digital TV has an inherent delay
> to it (for signal encoding or
Good work with the IERS folks Martin!
I agree with this approach, it is they way to do the authoritative side
of things. USNO and NIST is at best providing a service in this aspect.
Cheers,
Magnus
On 01/12/2015 10:53 PM, Martin Burnicki wrote:
Brooks Harris wrote:
IERS publishes this -
On 18/01/14 08:57, Brooks Harris wrote:
On 2014-01-17 11:15 PM, Magnus Danielson wrote:
Let's face it, this lump of orbital debris we call our home planet is
what we have as a reference and try to have common set of references.
This is our universe.
The universe is a little larger than
On 18/01/14 10:41, Brooks Harris wrote:
On 2014-01-18 12:43 AM, Magnus Danielson wrote:
On 18/01/14 08:57, Brooks Harris wrote:
On 2014-01-17 11:15 PM, Magnus Danielson wrote:
Let's face it, this lump of orbital debris we call our home planet is
what we have as a reference and try to have
On 14/01/14 16:37, Warner Losh wrote:
On Jan 14, 2014, at 8:05 AM, Steve Allen wrote:
In 1980 November the CCITT accepted UTC as the time scale for all
other telecommunications activities. In 2007 the BIPM contributed
document 7A/51-E to the ITU-R WP7A meeting regarding Question ITU-R
236/7
On 14/01/14 17:28, Poul-Henning Kamp wrote:
In message 0ccafa25-523e-4022-a993-4bc2d9fe5...@noao.edu, Rob Seaman writes:
A timescale that omits that connection should not be denoted
Universal Time of any kind, coordinated or not.
I would argue that any timescale called universal something
On 12/01/14 09:26, Brooks Harris wrote:
Thanks very much Steve. Great info
On 2014-01-11 10:45 PM, Steve Allen wrote:
On Sat 2014-01-11T21:43:02 -0800, Brooks Harris hath writ:
Any help getting to the bottom of this appreciated.
It's history, and it's confused. Measurement techniques
On 10/01/14 20:08, Harlan Stenn wrote:
Warner Losh writes:
...
A TAI realization of time_t isn't POSIX, which specifically proscribes
UTC.
I think you mean prescribes.
Regardless, today the POSIX standard has a mapping (or used to, last
time I checked I was unable to find that mapping,
Stephen,
Nice seeing you here!
On 03/01/14 21:45, Stephen Scott wrote:
Subject: Local insertion of leap seconds
I am new to this group so please excuse if this subject has been
previously covered.
As I understand the standard ITU-R TF.460-6 the leap second correction
is instantiated globally
On 03/01/14 22:20, Steve Allen wrote:
On Fri 2014-01-03T15:45:13 -0500, Stephen Scott hath writ:
2.)Video in North America and some other parts of the world is
Is currently described by section 5.3.2.13.1 of
ATSC-Mobile DTV Standard,
Part 2 -- RF/Transmission System Characteristics
Document
Hi Brooks,
Welcome to the list!
On 08/01/14 01:45, Brooks Harris wrote:
On 2014-01-07 03:40 PM, Poul-Henning Kamp wrote:
In message 52cc8c26.5090...@edlmax.com, Brooks Harris writes:
I fully understand time zone specifications are fractured. My objective
is to determine what standards are
On 06/01/14 19:40, Rob Seaman wrote:
PDFs of the slides from the talks yesterday (5 Jan 2014) are now available at:
http://www.cacr.caltech.edu/futureofutc/aas223/
Thanks for the pointer.
Reviewing Kara Warburton's presentation I have one comment.
The concept of a international
On 10/02/11 16:18, Tom Van Baak wrote:
Since the velocity of the atomic clock causes relativistic dilation,
surely it is not the altitude-above-sea-level, but the radial distance
from the earths axis that we are talking about???
1)
This seems to be a common misunderstanding. Realize that
the
On 07/02/11 20:10, Tom Van Baak wrote:
It is also why TAI's rate was adjusted in the 1990's to compensate for
the red-shifted data that had been collected at NIST in Boulder, since
it sits at about 5400' (1700m) above sea level (as well as other
facilities not at sea level).
Warner
Are you
On 01/07/2011 01:54 PM, Ian Batten wrote:
On 7 Jan 2011, at 00:28, Poul-Henning Kamp wrote:
In message 47d3bba6-a381-4dad-ad56-08e2b40fd...@pipe.nl, Nero Imhard
writes:
Each year should have at least two [...]
Have you considered that in asia one of them is likely to happen during
the
On 01/07/2011 03:37 PM, Rob Seaman wrote:
On Jan 7, 2011, at 6:08 AM, Zefram wrote:
Currently, a June leap second can occur while far-east markets are open.
There is nothing magic about the end of the month scheduling. It has some
advantages, that's all.
DST adjustments on the other hand
On 12/26/2010 12:04 AM, Poul-Henning Kamp wrote:
In message4d1676fe.32284.16eab...@dan.tobias.name, Daniel R. Tobias writes
:
So what that means is, even if you get the redefinition of UTC you're
loudly pushing for, the legislatures of the world are free to totally
ignore it and start using
On 12/24/2010 11:50 AM, Poul-Henning Kamp wrote:
In message4d14777e.8000...@rubidium.dyndns.org, Magnus Danielson writes:
The cached information isn't very useful when the GPS receiver has been
off for a while. Coming up on a cold-spare GPS receiver requires that
you wait.
True
On 12/23/2010 07:10 PM, Finkleman, Dave wrote:
Do any sources of precise, accrued time have a leap second warning bit
as DCF 77 does?Is the philosophy of leap second warning in DCF 77 a
good paradigm for helping implement the leap second broadly?
It helps, somewhat, but it would require
On 12/23/2010 08:50 PM, Warner Losh wrote:
On 12/23/2010 12:26, Tom Van Baak wrote:
GPS's model for handling of leap seconds is better: you
get both a UTC offset and a date when the leap second
is/was to be applied. Thus it is possible for you to obtain
TAI, GPS, or UTC out of a GPS receiver.
On 12/20/2010 12:21 AM, Tony Finch wrote:
On 19 Dec 2010, at 01:18, Magnus Danielsonmag...@rubidium.dyndns.org wrote:
This is true, if we by computing means POSIX.
There are many standards other than POSIX which use a POSIX timescale or one
equivalent to it. For example, NTFS, DNSSEC and
On 12/18/2010 07:23 PM, Poul-Henning Kamp wrote:
In message3b33e89c51d2de44be2f0c757c656c8809d66...@mail02.stk.com, Finklema
n, Dave writes:
ITU has UN funding.
Actually, I'm not even sure to what degree that is the case.
ITU charges fees for participation and their standards as well.
It
M. Warner Losh wrote:
In message: 445cb57a-6fcf-4933-a288-bd1521352...@noao.edu
Rob Seaman sea...@noao.edu writes:
: On Mar 10, 2010, at 10:12 PM, M. Warner Losh wrote:
:
: Maybe we just need to toss the word 'idealized' in there somehow.
:
: time_t is an idealized
Steve Allen wrote:
On Wed 2010-03-10T22:01:50 +, Michael Deckers hath writ:
Yes, the relationship between UTC and TAI is simple.
In the lingo of the atomic horologists I would say
the relationship between UTC(TAI) and TAI is simple.
Here UTC(TAI) means the version of UTC constructed
Matsakis, Demetrios wrote:
I have no privileged information and GPS receiver programming is not what I do,
but I also have
never known the ICD200 to be incorrect. Perhaps ten years ago, two timing
experts separately
informed me of great frustration they had writing their own GPS receiver
Joe Gwinn wrote:
Magnus,
At 5:10 PM +0200 10/10/09, Magnus Danielson wrote:
Joe,
Joe Gwinn wrote:
At 3:28 PM +0200 10/10/09, Magnus Danielson wrote:
M. Warner Losh wrote:
In message: 4acff759.3090...@rubidium.dyndns.org
Magnus Danielson mag...@rubidium.dyndns.org writes:
: M
M. Warner Losh wrote:
In message: 4acff759.3090...@rubidium.dyndns.org
Magnus Danielson mag...@rubidium.dyndns.org writes:
: M. Warner Losh wrote:
: In message: 13205c286662de4387d9af3ac30ef456afa8697...@embx01-wf.jnpr.net
: Jonathan Natale jnat...@juniper.net writes
M. Warner Losh wrote:
In message: 4ad0a3d9.2080...@rubidium.dyndns.org
Magnus Danielson mag...@rubidium.dyndns.org writes:
: Joe,
:
: Joe Gwinn wrote:
: At 3:28 PM +0200 10/10/09, Magnus Danielson wrote:
: M. Warner Losh wrote:
: In message: 4acff759.3090...@rubidium.dyndns.org
Steve,
Steve Allen wrote:
Within the recent CGSIC proceedings is the overview presentation by
Lewandowski of the BIPM.
http://www.navcen.uscg.gov/cgsic/meetings/49thmeeting/Reports/%5B39%5DTiming_WL_General.pdf
It includes one page plotting the various satellite time scales and
another showing
M. Warner Losh wrote:
In message: 13205c286662de4387d9af3ac30ef456afa8697...@embx01-wf.jnpr.net
Jonathan Natale jnat...@juniper.net writes:
: AFAIK, routers also just re-sych. The OS's are not capable of
: xx:xx:60 time. For reading router logs this is fine in most cases
: which is
Poul-Henning Kamp wrote:
In message 4ac87da2.4040...@rubidium.dyndns.org, Magnus Danielson writes:
Of course it cannot output a correct UTC solution until it has received
page 18 subframe 4, but it can store the leapsecond offset in
non-volatile RAM since last lock and for most of times
Poul-Henning Kamp wrote:
In message 4ac88906.30...@rubidium.dyndns.org, Magnus Danielson writes:
Poul-Henning Kamp wrote:
most of the times is simply not good enough.
Then you haven't understood the limits. GPS itself only works most of
the times.
The difference is, when GPS does
Steve Allen skrev:
Another atomic clock advert; good for 1 second in 25000 years.
http://news.thomasnet.com/fullstory/556476
If it fails by one second before then should I sue? Who?
NIST? Control Company of Texas?
How exactly does one get ISO 9001 certs that extend 25 millennia?
Or maybe
Zefram skrev:
Magnus Danielson wrote:
Thus, the TAI-UTC difference was 4.213170 + (40587-39126) x 0.002592s =
8.82 s.
Yes. This lets you calculate the number of *TAI* seconds since the
Unix epoch. There were 63072001.18 TAI seconds (exactly) in UTC's
version of 1970 and 1971
Zefram skrev:
M. Warner Losh wrote:
I'd phrase these like so:
UTC's 1970 and 1971 together had 63072001.18 SI seconds (exactly).
That's not quite true. They had that many *TAI* seconds, but TAI seconds
are not equal to SI seconds. TAI is an imperfect realisation of the
SI second.
Zefram skrev:
Magnus Danielson wrote:
Sorry, I think you over-interpret a poorly articulated formulation of
mine. If you think according to Honour the UTC definition from 1970 to
1972 and then the new leap-second based UTC definition from 1972 up to
current time then I think you should come
Zefram skrev:
Neal McBurnett wrote:
So I'll also celebrate the passing of 1234567890 UTC seconds
since January 1 1970, 00:00, which is 24 seconds earlier.
To be precise, you must also include the leap at the end of 1971,
of 10775800/10003 UTC seconds. That's 0.107758 TAI seconds, at
the
Zefram skrev:
Magnus Danielson wrote:
They also made a
correction for the accumulate error to restore phase relationships.
Except that this correction was faulty. By the mid 16th century, the
phase relationship between the seasons
Rob,
Rob Seaman skrev:
Magnus Danielson wrote:
time_t = d*86400 + h*3600 + m*60 + s
Just thought I'd note an alternate interpretation. In NOAO's widely
distributed image processing system (IRAF) a sexagesimal number is a
double precision floating point number, not an integer:
12:34
Zefram skrev:
M. Warner Losh wrote:
So time_t is effectively defined in POSIX to be:
d * 86400 + min(tod(x), 86399)
where d is the number of days since 01-01-1970, and tod is the second
since midnight within the day.
Actually it's simpler than that. The expression given by POSIX
Rob Seaman skrev:
Magnus Danielson wrote:
Hate to nitpick you, but that is a different representation, not a
different interpretation.
Even in technical documentation, words retain their broader meanings. I
was suggesting that instead of interpreting sexagesimal values as sets
of integers
M. Warner Losh skrev:
In message: 20090105102452.gj14...@fysh.org
Zefram zef...@fysh.org writes:
: M. Warner Losh wrote:
: So time_t is effectively defined in POSIX to be:
:
: d * 86400 + min(tod(x), 86399)
:
: where d is the number of days since 01-01-1970, and tod is the second
Rob Seaman skrev:
Adi Stav wrote:
We know that human tolerance to DUT is higher than 20 minutes because we
don't usually bother to compensate for apparent solar time. We know that
it is probably not much higher than one or two hours because time zones
generally have about that resolution. We
Poul-Henning Kamp skrev:
In message 421fb837-f23f-4a16-b6f4-f26d1c58c...@noao.edu, Rob Seaman writes:
It seems very unlikely that leap day will move from February. People
are fond of February. Also, a leap day at the end of December would
be December 32nd :-)
Which would break
M. Warner Losh skrev:
[[ continuation of a discussion from time-nuts ]]
In message: 496157c4.2050...@erols.com
Chuck Harris cfhar...@erols.com writes:
: Magnus Danielson wrote:
: Chuck Harris skrev:
: One of us is confused about what time_t is... I think it is
: you.
:
: I
Rob,
Rob Seaman skrev:
M. Warner Losh wrote:
POSIX doesn't support leap seconds.
I'm curious. Is this the only widely recognized shortcoming of POSIX?
I mean - either POSIX is riddled with numerous other mistakes - or this
is the only issue remaining to address before POSIX is perfected
John Hawkinson skrev:
(chiming in a bit late...)
Tony Finch d...@dotat.at wrote on Thu, 1 Jan 2009
at 06:10:59 + in
alpine.lsu.2.00.0901010602100.2...@hermes-1.csi.cam.ac.uk:
Wednesday's PM on Radio 4 included an item about the way the keepers of
the Big Ben clock handled the leap
Poul-Henning,
Poul-Henning Kamp skrev:
In message 5806d024-146d-43e4-aea0-a7aa514e3...@noao.edu, Rob Seaman writes:
M. Warner Losh wrote:
POSIX doesn't support leap seconds.
I'm curious. Is this the only widely recognized shortcoming of POSIX?
No, POSIX has numerous defects and bad
Tom Van Baak skrev:
An interesting NIST document from 2000 gives insight into the turf wars
about precision time scales.
http://tf.nist.gov/general/pdf/1429.pdf
The document makes it clear that GPS time was never designed to follow
UTC(USNO) (and by implication, TAI).
I think you're
Dear Brian,
b...@po.cwru.edu skrev:
From: Rob Seaman sea...@noao.edu
...
Like I keep saying, the mean solar day is trivial to compute from the
sidereal day. Look at it this way, there are really 366.25 days per
year. That extra day just gets sliced and diced among all the others.
Nice,
M. Warner Losh skrev:
In message: 1230843729.9555.2.ca...@glastonbury
Ashley Yakeley ash...@semantic.org writes:
: On Thu, 2009-01-01 at 09:41 -0700, Rob Seaman wrote:
: They can't be naively automated. The schedule is currently
: predictable 6 months in advance. Nobody has
Rob Seaman wrote:
On Sep 15, 2008, at 8:23 AM, Magnus Danielson wrote:
There where plans for converting Sweden to a base 8 country, but I don't
have the TAOCP I need at hand to give the details.
This sounds like either an urban legend or some isolated...
You obviously haven't read Donald
Adi Stav wrote:
(Hi, I'm Adi, long-time lurker, first-time caller)
On Mon, Sep 15, 2008 at 01:29:13AM -0700, Rob Seaman wrote:
In the absence of days and years, though, calculations that involve
only metric units are a lot easier than what we presently put up with.
Hence the prevalence of
On Sep 15, 2008, at 6:45 AM, Tony Finch wrote:
On Mon, 15 Sep 2008, Rob Seaman wrote:
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
In message
[EMAIL PROTECTED], Ma
gnus Danielson writes:
Everything is arbitrary as base scale and division.
Uhm no.
All bases larger than 2 are arbitrary and all scalings are arbitrary.
But base 2 represents the fundamental counting system, and as such is
is unique.
You may still
From: M. Warner Losh [EMAIL PROTECTED]
Subject: Re: [LEAPSECS] 2007-12-31 23:59:60 Z (sic)
Date: Tue, 01 Jan 2008 18:15:31 -0700 (MST)
Message-ID: [EMAIL PROTECTED]
In message: [EMAIL PROTECTED]
Steve Allen [EMAIL PROTECTED] writes:
: On Tue 2008-01-01T23:16:49 +, Tony Finch
56 matches
Mail list logo
