Re: [LEAPSECS] USNO predictions of UT1-UTC

2023-03-19 Thread Gerard Ashton via LEAPSECS
One of the reasons the implementation of the suppression of leap seconds was placed so far in the future is that GLONASS is said to rely on the current implementation of UTC. I wonder, if the international authorities decided to suppress a negative leap second but Russia decided that GLONASS couldn

Re: [LEAPSECS] leap minute or hour

2022-11-15 Thread Gerard Ashton via LEAPSECS
h daylight saving time and let people work out a schedule they decide is the best compromise between summer and winter. Gerard Ashton On Tue, Nov 15, 2022 at 5:27 AM Poul-Henning Kamp wrote: > > Clive D.W. Feather writes: > > > Stick with what people are used to, which is (

Re: [LEAPSECS] the big artillery

2014-11-06 Thread Gerard Ashton
If you want to go all the way back, Sumerian clay tablets arranged numbers in a grid that looked a lot like a modern spreadsheet, and one unit in a given column was equivalent to 60 units in the column immediately to the right. -Original Message- From: LEAPSECS [mailto:leapsecs-boun...@lea

[LEAPSECS] Notation for transmitted vs. paper time scales

2014-11-05 Thread Gerard Ashton
time label. TAI(NPL), on the other hand, is not a label used by officials, so its status as contemporaneous or adjustable is undefined except in the mind of some private individual that decided to use the notation. Gerard Ashton ___ LEAPSECS mailing list

Re: [LEAPSECS] the big artillery

2014-11-04 Thread Gerard Ashton
Of course Brooks Harris is free to define proleptic UTC any way he pleases within the confines of a document he has control over, including a post to this mailing list. But I think the term "proleptic UTC", outside the confines of a document that gives it a proprietary definition, could mean a vari

[LEAPSECS] Name of proleptic leap-secondless UTC

2014-10-15 Thread Gerard Ashton
r date and time of day at quasi-Greenwich, where each day consists of exactly 86,400 SI seconds? Gerard Ashton -Original Message- From: LEAPSECS [mailto:leapsecs-boun...@leapsecond.com] On Behalf Of Steve Allen Sent: Wednesday, October 15, 2014 11:07 AM To: Leap Second Discussion Li

Re: [LEAPSECS] Do lawyers care (know) about leap seconds?

2014-10-01 Thread Gerard Ashton
Steffen Nurpmeso wrote: > This approach would satisfy all parties: humans can continue to enjoy the cultural achievement of a clock that exactly describes their home planet, and engineers can use TAI for satisfying airplane schedule calculations for businessmen. "Businessmen" can keep whatever ti

Re: [LEAPSECS] Do lawyers care (know) about leap seconds?

2014-09-30 Thread Gerard Ashton
I think lots of contracts for the use of computers where time matters, such as online auction sites, contain language that the parties agree to use the time as maintained on a particular computer system, such as the electronic auction site's computers. -Original Message- From: LEAPSECS [ma

Re: [LEAPSECS] a big week for leaps at SG7 and WP7A

2014-09-30 Thread Gerard Ashton
Sorry, but I disagree with Tony Finch. The time period from June 30, 2012, 7:59:60 to June 30, 2012, 8:00:00, Eastern Daylight Time, did occur in the United States and any end user requiring such precision was legally obliged to observe it. -Original Message- From: LEAPSECS [mailto:leapsec

Re: [LEAPSECS] Leap second relationship to ISO 8601

2014-08-28 Thread Gerard Ashton
Tony Finch wrote > Right, and this is good for many purposes, e.g. recording times of events now or in the past. However for events in the future (meetings etc.) you need to record a time and a place, because the UTC offset and time zone rules are not predictable. Even better, local time can be u

[LEAPSECS] Leap second relationship to ISO 8601

2014-08-24 Thread Gerard Ashton
ISO 8601 is expensive; I obtained a copy before they started making it hard to find copies on the web. The wording of the standard is convoluted. Does anyone know if there is a highly-reputable, readable description of the standard that explains the extent to which the various choices are required,

[LEAPSECS] When will UT1 definition require replacement?

2014-03-20 Thread Gerard Ashton
The current relationship that UT1 must satisfy is given on page 78 of the 3rd ed. of the Explanatory Supplement to the Astronomical Almanac (among other places). I've modified it to live with the typesetting limitation of a mail list: ERA(t) = 2 pi (0.7790572732640 + 1.00273781191135448 t) Where

Re: [LEAPSECS] Definition of Standard time - Brooks Harris

2014-02-16 Thread Gerard Ashton
In US law (see http://www.law.cornell.edu/uscode/text/15/260a ) the time observed in each time zone is referred to as the standard time, even when the time is advanced during the summer. Obviously the language of the law differs from common usage. Gerry Ashton __

[LEAPSECS] Pedagogy & Greenwich

2014-02-10 Thread Gerard Ashton
We all know that "Greenwich Mean Time" is commonly used to describe UTC, UT1, and various similar time scales. Please check if I have estimated correctly. -The easternmost point of the London district of Greenwich is a the intersection of two roads, Maze Hill and Charlton Way. The coordinates are

[LEAPSECS] Apparent FCC endorsement of dropping leap seconds; FCC seeks comments

2014-01-30 Thread Gerard Ashton
This link was embedded in a newsletter to American amateur radio operators: http://transition.fcc.gov/Daily_Releases/Daily_Business/2014/db0128/DA-14-88 A2.pdf Instructions for commenting are provided here: http://hraunfoss.fcc.gov/edocs_public/attachmatch/DA-14-88A1.pdf Gerard Ashton

Re: [LEAPSECS] Future time

2014-01-19 Thread Gerard Ashton
" Excel may silently employ in searches. Gerard Ashton -Original Message- From: leapsecs-boun...@leapsecond.com [mailto:leapsecs-boun...@leapsecond.com] On Behalf Of Daniel R. Tobias Sent: Sunday, January 19, 2014 10:35 AM To: Leap Second Discussion List Subject: Re: [LEAPSECS] Future time

Re: [LEAPSECS] Birth date question

2014-01-18 Thread Gerard Ashton
are the chances the software designers considered all these scenarios? Gerard Ashton PS: (I'm fudging the minutes due to imperfect memory) Dispatched on an ambulance call at 2:30 AM. Returned to quarters 2:15 AM. ___ LEAPSECS mailing list LEAPSECS@le

Re: [LEAPSECS] presentations from AAS Future of Time sessions

2014-01-17 Thread Gerard Ashton
vital signs, and an automatic defibrillator does not advise any shock, the person can be declared dead in the field and need not be transported to the hospital. So synchronization of watches takes on new importance. Gerard Ashton -Original Message- From: leapsecs-boun...@leapsecond.com

Re: [LEAPSECS] LEAPSECS Digest, Vol 88, Issue 31

2014-01-15 Thread Gerard Ashton
E. G. Richards in "Mapping Time: The Calendar and its History" mentions the church was leary of negative numbers, and Hindu-Arabic numerals. He suggests one possible reason being that most of the people who could do arithmetic with Roman numerals were clergy, and they didn't want to lose their near

Re: [LEAPSECS] LEAPSECS Digest, Vol 88, Issue 31

2014-01-14 Thread Gerard Ashton
I think Matsakis's post illustrates an important point: who is in charge? Since no authority is in clear control of the definition of the Julian and Gregorian calendars, no authority is in a position to demand that December 31, 2000, be regarded as the last day of the 20th century. In the absence o

[LEAPSECS] Leap seconds and religion

2014-01-10 Thread Gerard Ashton
a fixed duration in SI seconds and use the 2011 value, the Gregorian calendar will be off by a day in about 3000 years. Whether it is reasonable to suppose any decision about leap seconds will endure for 3000 years is another issue. Gerard Ashton

Re: [LEAPSECS] drawing the battle lines

2013-05-09 Thread Gerard Ashton
e physical processes progress to the same degree. UT1 is satisfactory for most event recording and planning purposes. Gerard Ashton -Original Message- From: leapsecs-boun...@leapsecond.com [mailto:leapsecs-boun...@leapsecond.com] On Behalf Of Harlan Stenn Sent: Wednesday, May 08, 2013 10:36 P

[LEAPSECS] Testing computer leap-second handling

2012-07-09 Thread Gerard Ashton
nd by running a fake leap second into a test system that is sitting in a lab doing nothing but keep time. But a realistic test requires that the system under test be running a load as similar as possible to production systems. Gerard Ashton ___ LEAPSECS ma

Re: [LEAPSECS] Hetzner mail to customers: 1 megawatt more power due to leap second

2012-07-05 Thread Gerard Ashton
time it is medium-precision systems that failed; the coarse systems like Windows desktop systems that invoke their NTP client once a week did fine, and did fine when interfacing with medium-precision systems if the medium-precision systems were operating at all. Gerard Ashton -Original Message

Re: [LEAPSECS] Hetzner mail to customers: 1 megawatt more power due to leap second

2012-07-05 Thread Gerard Ashton
30/July 1? Will the people in charge of the new group of vulnerable systems be any more trustworthy than those in charge of the systems that failed? Gerard Ashton ___ LEAPSECS mailing list LEAPSECS@leapsecond.com http://six.pairlist.net/mailman/listinfo/leapsecs

[LEAPSECS] Accountability for failures and broken promises

2012-07-01 Thread Gerard Ashton
for making false promises? Gerard Ashton -Original Message- From: leapsecs-boun...@leapsecond.com [mailto:leapsecs-boun...@leapsecond.com] On Behalf Of Poul-Henning Kamp Sent: Sunday, July 01, 2012 2:04 PM To: Leap Second Discussion List Subject: Re: [LEAPSECS] telescope systems saw the

Re: [LEAPSECS] Telescope pointing

2012-06-08 Thread Gerard Ashton
So summarizing what I find in Steve's paper, and only concerning the pointing of the telescope and not the reporting results from the scope, large telescopes with guidance systems from the 1970s and 1980s have a guide camera field of view of 3 arcminutes, or a bit more. So if the telescope was aime

Re: [LEAPSECS] Telescope pointing

2012-06-08 Thread Gerard Ashton
] On Behalf Of Steve Allen Sent: Friday, June 08, 2012 9:58 AM To: Leap Second Discussion List Subject: Re: [LEAPSECS] Telescope pointing On 2012 Jun 8, at 04:32, Gerard Ashton wrote: > The list often discusses the fact that astronomers need UT1. Does > anyone know astronomer's requ

[LEAPSECS] Telescope pointing

2012-06-08 Thread Gerard Ashton
The list often discusses the fact that astronomers need UT1. Does anyone know astronomer's requirement for pointing accuracy. Does anyone know of a document that discusses how astronomers receive ΔUT1 and incorporate it in telescope pointing systems. (For telescope, read any astronomical instrument

Re: [LEAPSECS] Calendar authority

2012-04-05 Thread Gerard Ashton
Using the USA as an example, the constitutional provision giving the federal government authority over standards of weight and measure arguably gives it authority over time-of-day. Their success in regulating time zones and legal recognition of UTC as the basis of time tends to confirm this authori

Re: [LEAPSECS] Multi-timezone meetings

2012-01-25 Thread Gerard Ashton
offsets or boundaries. This suggest a desire for an algorithm that accepts as input a latitude and longitude of a point of interest, and a set of boundaries, and determines which of the regions the point of interest falls in. Does anyone know of such an algorithm? Gerard Ashton

[LEAPSECS] Leap second on analog watch

2012-01-24 Thread Gerard Ashton
2) for the vast majority of minutes, jump suddenly from second 59 to second 0 without stopping on second 60. Of course, such a watch would not really be analog, it would be digital with the display being by means of hands rather than Arabic numerals. Ger

Re: [LEAPSECS] ] Fractional US civil time period representation is brittle

2012-01-21 Thread Gerard Ashton
On 1/21/2012 9:13 AM, Poul-Henning Kamp wrote: In message<4f1ac413.1010...@comcast.net>, Gerard Ashton writes: Consider US eastern daylight time, June 30, 2012. [...] This will make certain time computations quite intricate. Representing the time as a simple floating point number may l

[LEAPSECS] ] Fractional US civil time period representation is brittle

2012-01-21 Thread Gerard Ashton
will make certain time computations quite intricate. Representing the time as a simple floating point number may lead to unexpected results. Gerard Ashton ___ LEAPSECS mailing list LEAPSECS@leapsecond.com http://six.pairlist.net/mailman/listinfo/leapsecs

Re: [LEAPSECS] Lets get REAL about time.

2012-01-20 Thread Gerard Ashton
rement errors made by the local device. Gerard Ashton On 1/20/2012 2:18 PM, Michael Sokolov wrote: Steve Allen wrote: TAI can be derived from UTC, GPS and other broadcast timescales, so availability is fine. Indications have been that BIPM will disagree violently with that statement. And

Re: [LEAPSECS] Lets get REAL about time.

2012-01-20 Thread Gerard Ashton
roach would be to subtract the transmission delay from the first-received server to the server that decides who won. It's difficult to predict what applications might require awareness of much shorter transmission delays. Gerard Ashton ___ LEAPSECS ma

Re: [LEAPSECS] Lets get REAL about time.

2012-01-20 Thread Gerard Ashton
For the smallest time resolution required, we might suppose that at some point in the future there might be a need to account for transmission delay from one part of a computer to another. The smallest location that I can imagine being of interest even in a future computer is the diameter of a hy

[LEAPSECS] End of plausible equivalence between UTC and GMT

2012-01-11 Thread Gerard Ashton
Please check my reasoning: The westernmost point of the London Borough of Greenwich appears to be at the intersection of the A200 and Deptford Church Street, which is west longitude 0° 1' 24". That corresponds to 5.6 seconds of time. Assuming the last possible leap second is in 2017, and that on

Re: [LEAPSECS] Straw men

2012-01-10 Thread Gerard Ashton
On 1/10/2012 12:06 PM, Ian Batten wrote: But unfortunately, UK civil time does not include a DST indicator Is there a law or rule that specifies how UK civil time ought to be written? Where can we examine the law or rule to see if there is a DST indicator or not? If there is no rule, how is th

Re: [LEAPSECS] Straw men

2012-01-09 Thread Gerard Ashton
On 1/9/2012 3:14 PM, Ian Batten wrote: And you do this not by looking up sunset in an almanac, a newspaper, a website, but by performing a calculation that relies on UTC-plus-leapseconds? Could you give me more detail of this? > ... No one has yet provided even the beginnings of the suggesti

Re: [LEAPSECS] Straw men

2012-01-09 Thread Gerard Ashton
On 1/9/2012 2:40 PM, Ian Batten wrote: So long as those all tick the same thing, its relationship to the rotation of the earth is, +/- several hours, irrelevant. No-one cares what the relationship between their watch/clock/computer and the sun is at anything other than the grossest scale Th

Re: [LEAPSECS] Straw men

2012-01-09 Thread Gerard Ashton
On 1/9/2012 10:55 AM, Ian Batten wrote: pace all the bizarre claims about bear hunting There are a number of laws and rules related to sunset and sunrise, including hunting, turning headlights on in automobiles, and being present in parks. No reliable evidence has been presented as to whether

Re: [LEAPSECS] "China move could call time on GMT"

2012-01-05 Thread Gerard Ashton
the legally binding national time scale. (Where legally binding means if you show up for a mandatory appointment with a government agency later that the required time, effectively reckoned from the broadcast time scale, you will be punished.) Gerard Ashton On 1/5/2012 7:03 PM, Poul-Henning

Re: [LEAPSECS] leap year rule ambiguity

2012-01-05 Thread Gerard Ashton
I don't think the original poster had this in mind, but there is a Revised Julian Calendar which is described in Wikipedia, and is equivalent to the Gregorian Calendar until AD 2800. It has been adopted by some Orthodox churches. It was defined at a church meeting in the 1920s (before the change

[LEAPSECS] New terminology will be needed.

2012-01-05 Thread Gerard Ashton
If the proposed change goes through, we will need a new term, perhaps "proleptic UTC2017", for post-2017 UTC extended backwards by subtracting as many minutes of 60 SI seconds as desired. Gerry Ashton ___ LEAPSECS mailing list LEAPSECS@leapsecond.com

Re: [LEAPSECS] Computer Network Time Synchronization, 2nd Ed.

2011-12-07 Thread Gerard Ashton
Although statements of birthdays are seldom accompanied by explicit statements of the time zone, the place of birth is usually available so the time zone can be reconstructed. As for what is recorded on a birth certificate, there is no telling what might be recorded; there are more than 14,000 k

[LEAPSECS] Cost not yet mentioned

2011-11-12 Thread Gerard Ashton
There are certain examinations that will test persons ability to perform navigation and land surveying calculations without the aid of the computer. In most cases the questions are kept secret, so only a select few will know whether the question pool will be affected by a leap second change. The

Re: [LEAPSECS] ITU Radiocommunication Assembly voting procedure

2011-11-04 Thread Gerard Ashton
A question that arose at the Wikipedia "Leap second" article is what is the voting procedure for the 2012 Radiocommuication Assembly? What percent must vote in the affirmative? Is it the required percent of member states, member states present, or member states that vote (where an abstention is

Re: [LEAPSECS] Coding this week, and a trick for timeouts over leap seconds.

2011-10-01 Thread Gerard Ashton
It would be OK if - the "heartbeats" occur much more frequently than 1 per second - the 1 second without a heartbeat criteria is arbitrary, and causing a false alarm because the actual period without a heartbeat is, for example, 998 ms. Gerard Ashton On 10/1/2011 12:23 PM, Paul S

Re: [LEAPSECS] Coding this week, and a trick for timeouts over leap seconds.

2011-10-01 Thread Gerard Ashton
possible that day. Gerard Ashton On 10/1/2011 5:16 AM, Paul Sheer wrote: I am busy implementing some heartbeat monitoring code between two machines. The spec calls for a 1 second recovery. Basically if I get no heartbeats for 1 full second then I should consider the peer system to have failed. To

[LEAPSECS] Politics

2011-09-27 Thread Gerard Ashton
rd of Weights and Measures". So is the calendar a standard of measure? If not does the US federal government have authority to regulate it? Maybe it is a power that belongs to the 50 states. Gerard Ashton ___ LEAPSECS mailing list LEAPSECS@l

Re: [LEAPSECS] Leap smear

2011-09-24 Thread Gerard Ashton
might or might not be accompanied by a de jure adoption. In the worst case, one will be adopted for most interactions, but a few legal interactions will follow the other.] Gerard Ashton On 9/24/2011 11:52 AM, Nero Imhard wrote: On 2011-09-20, at 09:11, Ian Batten wrote: On 19 Sep 2011, at

Re: [LEAPSECS] Legal violation for failure to know sunrise/sunset to nearest minute

2011-09-24 Thread Gerard Ashton
ision required for sunrise and sunset calculations, and timepieces, to satisfy the hunter who doesn't want to get caught. Then there is the question of the hunter who wishes to voluntarily obey the rules, even if he/she was sure of not getting caught. I expect minute precision would suffice fo

Re: [LEAPSECS] Legal violation for failure to know sunrise/sunset to nearest minute

2011-09-21 Thread Gerard Ashton
On 9/21/2011 7:59 AM, Daniel R. Tobias wrote: On 21 Sep 2011 at 7:53, Ian Batten wrote: hunting sunrise, hunting sunset, hunting daylight and hunting night all return zero hits. I don't really think that the presence or absence of enforced penalties for failing to precisely adhere to sunrise/s

Re: [LEAPSECS] Legal violation for failure to know sunrise/sunset to nearest minute

2011-09-20 Thread Gerard Ashton
urthouse, but the details of the case, such as how many minutes elapsed from the close of legal hunting hours to the time of the offense could be contained on a tape recording of the trial, perhaps never having been put in text form. Of cou

[LEAPSECS] Legal violation for failure to know sunrise/sunset to nearest minute

2011-09-20 Thread Gerard Ashton
polls of hunters and/or game wardens. Gerard Ashton ___ LEAPSECS mailing list LEAPSECS@leapsecond.com http://six.pairlist.net/mailman/listinfo/leapsecs

Re: [LEAPSECS] Leap smear

2011-09-20 Thread Gerard Ashton
On 9/20/2011 12:18 PM, Warner Losh wrote: On Sep 20, 2011, at 9:51 AM, Gerard Ashton wrote: On 9/20/2011 11:24 AM, Poul-Henning Kamp wrote: In message<4e78aa49.5060...@comcast.net>, Gerard Ashton writes: On 9/20/2011 5:53 AM, Poul-Henning Kamp wrote: Earth orientation is one factor

Re: [LEAPSECS] Leap smear

2011-09-20 Thread Gerard Ashton
On 9/20/2011 11:24 AM, Poul-Henning Kamp wrote: In message<4e78aa49.5060...@comcast.net>, Gerard Ashton writes: On 9/20/2011 5:53 AM, Poul-Henning Kamp wrote: Earth orientation is one factor in the time of sunrise and sunset, and that is important at perhaps minute precision for many pu

Re: [LEAPSECS] Leap smear

2011-09-20 Thread Gerard Ashton
On 9/20/2011 5:53 AM, Poul-Henning Kamp wrote: B) Earth Orientation is not important at sub-half-hour precision. I think a more precise statement of this is that earth orientation at sub-half-hour precision does not seem to be a requirement for most recurring events that are scheduled at a fixe

Re: [LEAPSECS] leap smear

2011-09-18 Thread Gerard Ashton
On 9/18/2011 7:02 PM, Tom Van Baak wrote: This may or may not be a boundary condition. The fundamental system engineering problem is that there are two different types of time, two kinds of clock. Rob, You keep saying this, but there's only one kind of clock and one kind of time. When you get

Re: [LEAPSECS] the abbreviation UTC

2011-08-18 Thread Gerard Ashton
On 8/18/2011 4:30 AM, mike cook wrote: Could this be a good argument for getting parking ticket offences thrown out? Under current rules, UTC is an approximation to mean solar time at some meridian that passes through the grounds of the Royal Observatory, Greenwich (although not necessar

Re: [LEAPSECS] LEAPSECs and Wikipedia

2011-08-15 Thread Gerard Ashton
Wikipedia can be edited by almost anyone, but the regulars there will look to see if any change is supported by a citation to a reliable published source, since there is no mechanism to establish that a particular contributor has any relevant qualifications. So a change is likely to stick, if an

Re: [LEAPSECS] DUT1

2011-08-04 Thread Gerard Ashton
One does not use the 100 Hz tone, one counts doubled ticks in the first 16 seconds of each minute. Right now ticks 9, 10, and 11 are doubled, so DUT1 is -0.3 s. See http://www.nist.gov/pml/div688/grp40/wwv_format.cfm#ut1 for more details. I made an error when I wrote WWVB, I meant WWVH. Of cours

[LEAPSECS] DUT1

2011-08-04 Thread Gerard Ashton
It is not necessary, at least in the case of WWV and WWVB, to have special equipment beyond a short wave radio to decode DUT1. It can be done by ear. Timings of sun and star observations can be done with a hand-operated stop watch to a precision of 0.1 s, the same precision as DUT1. (Not to say th

Re: [LEAPSECS] Caveat emptor!

2011-04-11 Thread Gerard Ashton
On 4/11/2011 2:50 PM, Tony Finch wrote: Rob Seaman wrote: No. The words "Universal Time" will be ambiguous. Under any given circumstances listeners will ask whether their usage in a document refers to the redefined UTC, or to the original UTC (documents are forever), or to some other variatio

Re: [LEAPSECS] L-format. Re: Crunching Bulletin B numbers (POSIX time)

2011-02-21 Thread Gerard Ashton
On 2/21/2011 10:49 AM, Paul Sheer wrote, in part: No, it's my own idea. Hereby released to the world: "2010-02-21 09:40:27 -0600 L0024" I hereby name it "timestamp L-format". It solves the problem of absolutely specifying a future time where you don't know how many leap seconds there will be

Re: [LEAPSECS] Crunching Bulletin B numbers

2011-02-19 Thread Gerard Ashton
On 2/19/2011 10:24 AM, Joe Gwinn wrote, in part: I have not been following the proposal in detail, but a key issue to the POSIX community is that their timescale must be implementable in a totally isolated machine, one having no GPS or internet access. There are other requirements as well. Th

Re: [LEAPSECS] What's the point?

2011-02-14 Thread Gerard Ashton
This is not just a computing issue it is a time keeping issue. People frequently apply time zones to times mentally, so there should be an integer number of hours between the internationally accepted basis for time and the civil time in any particular place. Countries that ignore this will suff

Re: [LEAPSECS] What's the point?

2011-02-08 Thread Gerard Ashton
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 measur

[LEAPSECS] Government ability to carry out policy

2011-02-08 Thread Gerard Ashton
Poul-Henning Kamp wrote: History has shown that very few, if any, governments have been unable to carry through their more or less well thought out policies in this area. Well, it can be difficult to identify government policies; various office holders and agencies tend to scurry about follow

Re: [LEAPSECS] LEAPSECS Digest, Vol 51, Issue 23

2011-02-08 Thread Gerard Ashton
On 2/8/2011 9:51 AM, Clive D.W. Feather wrote: Gerard Ashton said: A secular change to civil time that would be perceptible without the aid of a clock has never been introduced, How about those places that moved timezone permanently. A single permanent time zone change is not a secular

Re: [LEAPSECS] LEAPSECS Digest, Vol 51, Issue 23

2011-02-08 Thread Gerard Ashton
On 2/8/2011 6:42 AM, Tony Finch wrote: On Mon, 7 Feb 2011, Rob Seaman wrote: 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. Stephen should add this to the consensus building list. Does that m

Re: [LEAPSECS] LEAPSECS Digest, Vol 51, Issue 23

2011-02-07 Thread Gerard Ashton
On 2/7/2011 2:49 PM, Tony Finch wrote: On Mon, 7 Feb 2011, Finkleman, Dave wrote: This discussion exposes the fact that we don't all have to work in the same reference frame or time system - as long as we understand what we are using and make it clear to users. Though the whole point of univer

Re: [LEAPSECS] Consensus building?

2011-02-03 Thread Gerard Ashton
On 2/3/2011 9:00 AM, Clive D.W. Feather wrote: Warner Losh said: SI - the SI-second is a standardised unit of measurement - the SI-second is currently defined as a fixed number of transitions of a caesium atom - the current definition of the SI-second was ratified in 1967 Agreed. I'd also add

Re: [LEAPSECS] Consensus building 2

2011-02-02 Thread Gerard Ashton
The point below should be * definition: UTC-1972-day - a duration of 86399, 86400, or 86401 seconds. On 2/2/2011 8:50 PM, Stephen Colebourne wrote: * definition: UTC-1972-day - a duration either 86400 SI-seconds or 86401 SI-seconds long ___ LEAPSECS

[LEAPSECS] So-called SI minute, hour, day

2011-02-02 Thread Gerard Ashton
According to the 2008 edition of the NIST Special Publication 811, page 8, day, hour, and minute "are not part of the SI" but "are accepted by the CIPM, and thus by this Guide, for use with the SI." So I guess that makes them CIPMFUWSI days, hours, and minutes. Gerry Ashton ___

Re: [LEAPSECS] Consensus building?

2011-02-02 Thread Gerard Ashton
On 2/2/2011 1:44 PM, Stephen Colebourne wrote: You're reading more into the statement than is intended by trying to interpret them as a time-scale or clock. I'm defining a unit of SI-based-minute that is a multiple of 60 of the unit SI-second. No more no less. I think when trying to list stateme

Re: [LEAPSECS] Consensus building?

2011-02-02 Thread Gerard Ashton
On 2/2/2011 11:47 AM, Stephen Colebourne wrote: Statements so far - disgree or add please (in particular something on UT1/UT/etc as I will only get it wrong...): General: - the terms seconds, minutes, hours and days are overloaded, thus pedantic and explicit terms are used here SI - the SI-seco

Re: [LEAPSECS] Consensus building?

2011-02-02 Thread Gerard Ashton
Change and add: - the solar-day is a commonly used unit of measurement - TAI and parallel time scales have been defined so that in modern times the difference between an atomic day and a solar day is not perceptible without the aid of timepieces. Popular acceptance of atomic days as a basis of

Re: [LEAPSECS] Meeting with Wayne Whyte

2011-02-01 Thread Gerard Ashton
On 2/1/2011 3:24 PM, Michael Deckers wrote, in part: On 2011-02-01 11:35, Poul-Henning Kamp wrote: How could the unpredictable difference TAI - UTC be a problem if everybody (including every computer) just kept UTC? Michael Deckers. ___ LE

Re: [LEAPSECS] Meeting with Wayne Whyte

2011-02-01 Thread Gerard Ashton
It may not have been your intention, but from now on I will hear whatever you type in a particular accent. Gerry Ashton On 2/1/2011 5:09 AM, Poul-Henning Kamp wrote: In message, Mark Calabretta writes: OK Tom, I'm prepared to accept those odds. I'll give you $16 if you correctly predict the

Re: [LEAPSECS] Java JSR-310 Instant class: suggested changes

2011-01-29 Thread Gerard Ashton
ch. Before that, the time scale will be the biological clock of the person recording the event, reduced by an estimate of the recorder's longitude to Greenwich. Gerry Ashton On 1/29/2011 5:31 PM, Stephen Colebourne wrote: On 29 January 2011 15:06, Gerard Ashton wrote: I suggest the follow

Re: [LEAPSECS] Java JSR-310 Instant class: suggested changes

2011-01-29 Thread Gerard Ashton
I suggest the following replacement for parts of the the Instant description. I offer the replacement because the wording of UTC-SLS clearly only applies after 1 January 1972, and that scale should be regarded as undefined prior to that date. This is the Javadoc for Instant, the most widely used

Re: [LEAPSECS] Java: ThreeTen/JSR-310

2011-01-29 Thread Gerard Ashton
On 1/29/2011 3:27 AM, Stephen Colebourne wrote, in part: It is my opinion, coming from an open source background, that if the body currently defining leap seconds stops doing so with less than 100% consensus, then the leap second defining process would be forked. Some other person/body/open sour

Re: [LEAPSECS] Conversational caffeine

2011-01-28 Thread Gerard Ashton
On 1/28/2011 5:47 PM, Rob Seaman wrote (in part): Civil time is based on the synodic day. Interval timekeeping requires a different timescale. Pretending one is the other is not a requirement. Rob ___ LEAPSECS mailing list LEAPSECS@leapsecond.com

Re: [LEAPSECS] Java: ThreeTen/JSR-310

2011-01-28 Thread Gerard Ashton
-second precision without needing sub-second accuracy. Gerard Ashton On 1/28/2011 3:42 PM, Tom Van Baak wrote, in part: I partly ask because for the class of users who are willing to be close enough to UTC (say within 1 second), there are no leap second issues, ever. This covers most users on the

Re: [LEAPSECS] Java: ThreeTen/JSR-310

2011-01-28 Thread Gerard Ashton
When it comes to finding a standard to smooth UTC in order to hide leap seconds for purposes of the Java Instant class, I would be tempted to find a computer architecture that handles leap seconds properly, and propose a standard that can be implemented as easily as possible on that architectur

Re: [LEAPSECS] Java: ThreeTen/JSR-310

2011-01-27 Thread Gerard Ashton
The issue I have with the Java classes explained by Stephen Colebourne is the use of UTC-SLS. This is a proposal that exists on an individual's web site. The existence and reputation of the website are subject to the future actions of the individual. It is also available as an inactive IETF dra

[LEAPSECS] Pragmatic solution (sometimes)

2011-01-14 Thread Gerard Ashton
I was talking to the IT manager for a town in Connecticut, USA. I asked if town residents could pay taxes and fees online. He said they could. I asked how they knew if a deadline had been met and whether late penalties should be added. He said that the town officials were lenient, and if the pa

[LEAPSECS] Problem for comparison: workers in multiple time zones

2011-01-01 Thread Gerard Ashton
In this list, various time problems that people have learned to live with without really solving are sometimes mentioned, in order to put the leap second problem into perspective. I would like to mention one more. A company has its employees fill out a time sheet on a computer (or equivalently

Re: [LEAPSECS] New Year in Times Square

2011-01-01 Thread Gerard Ashton
The ball dropping in Times Square illustrates an exacerbation of something that has always been true. It is not possible in the USA, now that digital TV is pervasive, to broadcast a truly "live" event. The ball must drop with an accuracy of about 1 second to satisfy a million people who are pre

[LEAPSECS] Computing platform that recognizes leap seconds.

2010-12-20 Thread Gerard Ashton
There have been allusions to computer systems other than POSIX which recognize leap seconds. I thought I would point out a partial example of one. The z/Architecture Principles of Operation (descendant of the System/370) explains in chapter 4 the operation of the time of day clock. The publi

[LEAPSECS] WWVB receivers, legal time, WWV

2010-12-19 Thread Gerard Ashton
The idea that consumer grade WWVB receivers will become obsolete supposes that legal time will be a fixed (except for daylight savings time) offset from UTC, and UTC continues to include leap seconds. If WWVB were to broadcast the proposed TI instead of UTC, the old receivers would display TI-b

[LEAPSECS] Documentation review as important as code review

2010-12-18 Thread Gerard Ashton
Poul-Henning Kamp made some inquiries about how quickly Rob could review code. I suggest this question misses a few important items. 1. Documentation. If the documentation for any given system claims UTC agrees with UT1 or GMT within 0.9 s, there is the danger that some programmer who only loo

Re: [LEAPSECS] A consolidated approach.

2010-12-15 Thread Gerard Ashton
If ISO does publish a standard, I hope they distribute it better than they did ISO 8601. In that case, they made it absurdly expensive, and then published a free summary of it on their website claiming it was the best way to write dates, but left out so many important details that anyone who re

[LEAPSECS] Affect of Y2K on programmers' attitude toward time documents

2010-12-10 Thread Gerard Ashton
One effect I recall from the Y2K prevention effort actually relates to 29 February 2000. There was considerable discussion among programmers as to whether that date existed or not, and there was enough disagreement among the computer language manuals and the like that programmers lost confidenc

Re: [LEAPSECS] php breaks if UTC has no leap seconds?

2010-12-10 Thread Gerard Ashton
On 12/10/2010 10:15 AM, Peter Vince wrote: Hello Paul, I'd be interested if you have some examples of of Y2K bugs that were fixed before they became a problem. In my very limited experience, I wasn't affected by any, nor aware of them. Peter On 10 December 2010 01:55, Paul Sheer

Re: [LEAPSECS] it's WP7A week in Geneva

2009-10-05 Thread Gerard Ashton
I find it remarkable that one group of time users chose a particular time dissemination mode (GPS) and made the typical array of poor decisions / errors with software. They also create a rather arbitrary demand of obtaining correct UTC within 5 minutes of installing hardware that has been sitting o

Re: [LEAPSECS] A new use for Pre-1972 UTC

2009-02-17 Thread Gerard Ashton
Rob Seaman wrote in part: Actually, there is a failure of the current scheme in the document. A notary is per country/state pair. But about a third of the U.S. states and presumably many provinces in other countries are split by timezones Notaries are usually allowed to

Re: [LEAPSECS] A new use for Pre-1972 UTC

2009-02-17 Thread Gerard Ashton
Rob Seaman wrote in part: Creating an ID that is guaranteed unique is not a trivial task, especially if (as one suspects is true here) a central server is out of the question. I'm not familiar with the details of OID, but in general, it would be desireable to have the option to perfor

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