At 12:32 PM 7/20/2005, Chris O'Byrne wrote...
>Mike wrote
>
>> They missed the event by 7 seconds instead of under 1.
>
>A one second difference in UT1 does not correspond to a one second
>difference in the observed time of the eclipse in an atomic timescale
>... I now think that is wrong - I now
In message: <[EMAIL PROTECTED]>
[EMAIL PROTECTED] (Mike S) writes:
: I suppose you believe that DST makes the day longer, too.
Clearly, the extra hour of daylight will burn up the crops!
Warner
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At 07:39 AM 7/20/2005, Poul-Henning Kamp wrote...
>In message <[EMAIL PROTECTED]>, Mike S writes:
>
>>I suppose you believe that DST makes the day longer, too.
>
>No Mike, but I belive some crania are to thick to make it
>worth arguing with the inhabitant.
You misspelled the word "too" in your sel
In message <[EMAIL PROTECTED]>, Mike S writes:
>I suppose you believe that DST makes the day longer, too.
No Mike, but I belive some crania are to thick to make it
worth arguing with the inhabitant.
Welcome to my kill file.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
[EMAIL PROTECT
At 06:38 AM 7/20/2005, Poul-Henning Kamp wrote...
>Experience with daylight savings time and timezones indicate that
>it can be two hours off and people still survive.
That's a red herring.
DST isn't applied to UTC.
DST and timezones offset time by a fixed, well defined amounts. As long as a
t
In message <[EMAIL PROTECTED]>, "M. Warner Losh" writes:
>In message: <[EMAIL PROTECTED]>
>OK. For leap years, we know from 1500ish until ~4000 (assuming they
>change it) the rule will be:
>
> if (y % 4 == 0) && (y % 100 != 0 || y % 400 == 0))
> leap-year
> else
>
In message: <[EMAIL PROTECTED]>
"Chris O'Byrne" <[EMAIL PROTECTED]> writes:
: > >Yes. Leap seconds are absurd enough, leap hours are 3,600 times more
: > >absurd!
: >
: > You forgot to extrapolate that statement to leap days.
:
: Leap days are extrapolatable for the next 1,000 years
At 08:48 AM 7/19/2005, Chris O'Byrne wrote...
>Now, can you come up with a scenario extolling the virtues to the
>average person of leap seconds? Or a scenario in which an
>ever-so-slightly variable second being used by a member of the public
>proves disasterous?
Your scenario has nothing to do wi
At 05:56 AM 7/19/2005, Chris O'Byrne wrote...
>The rules are those of "simple arithmetic". You are not allowed to use
>lookup tables, and you are not allowed to use quadratic equations. You
>are in a hotel, without access to your normal sources of reference,
>without access to a calculator, sittin
In message <[EMAIL PROTECTED]>, "M. Warner Losh" writes:
>: 2005-07-18T12:34:56Z (UTC)
>: 2005-07-18T12:35:28A (TAI - same instant)
>:
>: Multiple timescales will always exist. We should acknowledge that
>: fact and move on.
>
>The reason that 'Z' is used for UTC is that A-X are used
In message: <[EMAIL PROTECTED]>
[EMAIL PROTECTED] (Mike S) writes:
: At 04:36 PM 7/18/2005, M. Warner Losh wrote...
:
: >: By attempting to ignore an intrinsic reality, we are making such
: >: issues more likely, not less. How about an extension to ISO 8601
: >: that would permit
At 04:36 PM 7/18/2005, M. Warner Losh wrote...
>: By attempting to ignore an intrinsic reality, we are making such
>: issues more likely, not less. How about an extension to ISO 8601
>: that would permit distinguishing timescales, something like:
>:
>: 2005-07-18T12:34:56Z (UTC)
>:
In message: <[EMAIL PROTECTED]>
Rob Seaman <[EMAIL PROTECTED]> writes:
: Your program could have been layered on TAI.
Layering the program on TAI is likely a non-starter. Since the
cellular networks use UTC, he'd still need to know about leapseconds.
There's no way around that require
At 08:34 AM 7/18/2005, Chris O'Byrne wrote...
>>>The kind of "simple arithmetic" that I was thinking about precludes
>>>the use of look-up tables.
>>
>> Yet you consider quadratic equations to be "simple arithmetic?"
>
>Simple arithmetic would give an order of magnitude better ESTIMATE. That
>ESTI
In message: <[EMAIL PROTECTED]>
Bill Janssen <[EMAIL PROTECTED]> writes:
: Instead of trying, the impossible, task of coming up with a time scale
: that everyone is happy with
: why not come up with something easier, such as stabilizing the
: rotational rate of mother Earth.
It has g
Instead of trying, the impossible, task of coming up with a time scale
that everyone is happy with
why not come up with something easier, such as stabilizing the
rotational rate of mother Earth.
:-)
Bill K7NOM
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Thanks to all for the excellent discussion - over the past five years
I've seen much less diplomatic discussions on the issues. It has
never bothered me that folks hold a diversity of opinions on UTC -
time is a deeply interesting subject worthy of our best efforts. Any
solution(s) worth
My apologies to those who are offended by a common-sense
application of UTC as civil time. I apologize for not
taking your argument seriously but adding it to the medical
irritations in my life. I have no right to comment on the
amount of traffic in this list.
I measure caliber by correctness, com
At 06:24 PM 7/17/2005, [EMAIL PROTECTED] wrote...
>>>simple arithmetic with a timescale with a variable second would give an
>>>order of magnitude better estimate of the amount of time between 2005 Dec 31
>>>23:59:59.9 and 2006 Jan 01 00:00:00.1 than UTC does!
>>
>>UTC will tell you that there is E
At 08:25 AM 7/17/2005, [EMAIL PROTECTED] wrote...
>simple arithmetic with a timescale with a variable second would give an order
>of magnitude better estimate of the amount of time between 2005 Dec 31
>23:59:59.9 and 2006 Jan 01 00:00:00.1 than UTC does!
UTC will tell you that there is EXACTLY 1
In message <[EMAIL PROTECTED]>, "Bill Hawk
ins" writes:
>Perhaps some of you didn't understand the paragraph on
>process control systems, or perhaps you are still pondering.
It sounds a lot more like you have no idea what caliber of
people you are talking to Bill.
I have spent 25 years doing all
Perhaps some of you didn't understand the paragraph on
process control systems, or perhaps you are still pondering.
Let me restate the solution for those who can only get UTC
but need monotonically increasing wall clock time.
Note that "you" is no one specific, just not me.
1. Provide your compu
M. Warner Losh said,
"Time sources are in UTC, and you need a leapsecond
count to recover TAI."
Is this what all the fuss is about? UTC is all that is distributed
and you have to do a subtraction to get TAI?
He also said, on the subject of NTP and one days notice,
"So while the computers are lik
In message: <[EMAIL PROTECTED]>
"Bill Hawkins" <[EMAIL PROTECTED]> writes:
: My little program served the needs of civil time. It backs up
: at 59 seconds because the display software can't handle 60.
: That seems close enough for civil work. If you must have
: monotonically increasing
Oh, dear. I have made a mistake. I had not realized that
I was dealing with purists who love to argue.
Here are my understandings of the time scales:
UTC: Civil time, what most people mean by time of day. Was
determined by star crossings at Greenwich, now related to
TAI in that both use the same
In message: <[EMAIL PROTECTED]>
"M. Warner Losh" <[EMAIL PROTECTED]> writes:
: In message: <[EMAIL PROTECTED]>
: [EMAIL PROTECTED] (Mike S) writes:
: : At 06:36 PM 7/16/2005, Robert Lutwak wrote...
: : >As for concern that people in 10,000 years won't conform to having the s
In message: <[EMAIL PROTECTED]>
[EMAIL PROTECTED] (Mike S) writes:
: At 06:36 PM 7/16/2005, Robert Lutwak wrote...
: >As for concern that people in 10,000 years won't conform to having the sun
come up 15 minutes earlier, I'd say y'all are underestimating the power of
adaptive evolutio
At 06:36 PM 7/16/2005, Robert Lutwak wrote...
>As for concern that people in 10,000 years won't conform to having the sun
>come up 15 minutes earlier, I'd say y'all are underestimating the power of
>adaptive evolution.
Innumeracy or deliberate and egregious understatement? AM and PM would be
re
At 06:12 PM 7/16/2005, Bill Hawkins wrote...
>Um, would you care to point out the more serious bugs?
>
>Bill
The UTC time sequence with your code would go (at the 1 second interrupts):
23:59:59.0
23:59:59.0
00:00:00.0
Leading to ambiguous (duplicated) timestamps. The correct solution is closer t
[EMAIL PROTECTED] (Business)
(978) 927-4099 FAX [EMAIL PROTECTED] (Personal)
(339) 927-7896 Mobile
- Original Message -
From: "Bill Hawkins" <[EMAIL PROTECTED]>
To: "Discussion of precise time and frequency measurement"
Sent: Saturday, July 16,
In message: <[EMAIL PROTECTED]>
"Bill Hawkins" <[EMAIL PROTECTED]> writes:
: Um, would you care to point out the more serious bugs?
(1) Leap seconds can happen at the end of any month, not just
june/decemeber.
(2) Leap seconds can be both positive and negative
(3) Local time is typ
gt;From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
>Sent: Saturday, July 16, 2005 3:47 PM
>To: [EMAIL PROTECTED]; Discussion of precise time and frequency measurement
>Subject: Re: [time-nuts] Re: UTC - A Cautionary Tale
>
>
>In message <[EMAIL PROTECTED]>, "Bil
Um, would you care to point out the more serious bugs?
Bill
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Sent: Saturday, July 16, 2005 3:47 PM
To: [EMAIL PROTECTED]; Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Re: UTC - A
In message <[EMAIL PROTECTED]>, "Bill Hawk
ins" writes:
>Garbage is in the eye of the beholder.
Indeed.
That your "I'm gonna show those morons!!!" example contains serious
bugs in the leap second handling makes this one of my most treasured
emails in this entire debate.
Welcome to category 3) B
Robert Lutwak said,
"It ain't "...a few lines." Properly dealing with timezones, daylight
savings, and leapseconds can easily run into thousands of lines of code, by
the time you include of of the oddball irregularities around the world. Not
only does the clockmaker have to implement all of this
In message <[EMAIL PROTECTED]>, Rob Seaman writes:
>Why are you so convinced that there couldn't possibly be negative
>ramifications associated with the unexamined assumptions underlying
>the distinction between time-of-day and interval time? Or simply
>with the unwarranted assumption that
In message <[EMAIL PROTECTED]>, "Bill Hawk
ins" writes:
>Anybody *know* how The Clock of the Long Now proposed
>to handle leap seconds over 10,000 years? Please note
>the emphasis on "know." We have enough shared
>ignorance as it is, from myself included.
I don't think the intra-day timekeeping w
Poul-Henning Kamp said,
"Hopefully not too many people will be hurt trying to convince you."
The great majority of people do not know that leap seconds exist.
They set their watches by their WWVB (or whatever) inexpensive
atomic clock receiver if they care about time at all.
If you don't have le
Anybody *know* how The Clock of the Long Now proposed
to handle leap seconds over 10,000 years? Please note
the emphasis on "know." We have enough shared
ignorance as it is, from myself included.
The Moon does not cause leap seconds. That effect is
measured in milliseconds per century.
John, shou
Hopefully not too many people will be hurt trying to convince you.
Amen. And hopefully any resulting lawsuits will assign blame and
damages where they belong - with the financial backers and managers
and designers of systems that failed to implement the appropriate
international standard.
In message <[EMAIL PROTECTED]>, Rob Seaman writes:
>There will be no need to reeducate anybody if the civil time standard
>is left unchanged.
That is why I'm sort of happy we got a leap-second next january:
that will allow us to judge claims like yours.
Hopefully not too many people will be hu
On Jul 16, 2005, at 12:07 AM, Poul-Henning Kamp wrote:
No, you can not tell me today how many seconds between now and
2010-01-01 00:00:00 UTC and that is the whole problem.
That is *part* of the problem - a part that is intrinsic to living
within a non-inertial reference frame. Folks who n
In message <[EMAIL PROTECTED]>, Mike S writes
:
>_All_ uses of civil time expect it to be synchronous with astronomical
>time, to varying degrees of precision. An absence of leap (seconds)
>will eventually cause it to be dark at noon, unadjusted use of the
>current formula for leap days will eventu
At 07:37 AM 7/16/2005, Robert Lutwak wrote...
>Personally, I'd like to eliminate timezones and daylight savings, as well as
>leapseconds. Why is it so important that everyone on the planet clock in at 8
>a.m. or that we all have dinner at 6 p.m. ?
That's a short term view. Eliminate the leap se
Rob Seaman wrote:
Straightforward algorithms (a few lines of C) can convert standard time to
local time and mean time to apparent time.
It ain't "...a few lines." Properly dealing with timezones, daylight
savings, and leapseconds can easily run into thousands of lines of code, by
the time
In message <[EMAIL PROTECTED]>, Rob Seaman writes:
>Nobody has invested ten cents in a
>good luck safety net toward the retirement of leap seconds.
The entire problem is that people have not spent ten cents on
properly handling leap seconds.
>The public - including folks like applications prog
In message <[EMAIL PROTECTED]>, Rob Seaman writes:
>No - by standardizing the meaning of the terms, we made it possible
>to easily convert between all the flavors of solar time using closed
>form algorithms accurate to whatever precision is required.
No, you can not tell me today how many sec
Warner Losh says:
We already have ambiguity in when something occurs, as defined by
Earth. Each timezone is 15 degrees wide, and thus something may
happen at 11:59:59pm local standard time, but really happen at
12:01:01am the next day 'solar' time.
Ambiguity cuts both ways. Standard tim
At 07:07 PM 7/15/2005, M. Warner Losh wrote...
>In message: <[EMAIL PROTECTED]>
>Rob Seaman <[EMAIL PROTECTED]> writes:
>: Historians may care deeply about whether some event
>: occurred on one day (as defined by the Earth) as opposed to another
>: day (as defined by mid-level inter
In message: <[EMAIL PROTECTED]>
Rob Seaman <[EMAIL PROTECTED]> writes:
: Historians may care deeply about whether some event
: occurred on one day (as defined by the Earth) as opposed to another
: day (as defined by mid-level international bureaucrats). Religious
: issues anybody
Last time I heard anybody jump into an argument with "surely" was in college
in 1958. Harrumph. Surely this list hasn't been hit with a group
of sophomores because someone posted the address on a campus bulletin
board.
Chris O'Byrne said,
"Civil time should be based on a quadratic formula involvin
In message: <[EMAIL PROTECTED]>
"Chris O'Byrne" <[EMAIL PROTECTED]> writes:
: The rest of us need a useable timescale where the sun is basically due
: south in Greenwich at 12:00:00.000. However, since the equation of time
: introduces a natural error of +/- 15 minutes or so in the exac
Surely the way to look at the timescales and leap second issues are to
look at the requirements and go from there.
It seems to me that there are two basic requirements. Scientists of
various colours need a regular timescale, and are not particularly
concerned if the sun is above or below the horiz
In message <[EMAIL PROTECTED]>, Rob Seaman writes:
>But note that this includes millions of amateur astronomers as well.
>If you haven't looked recently at commercially available amateur
>telescopes, they are paragons of civil time handling.
I know. I upgraded my old 4" Newtonian to an ETX1
In message <[EMAIL PROTECTED]>, "Jack Hudler" writes:
If they can tell the difference, why do they use the word "time"
when they keep telling us that "everybody" needs earth rotational
orientation ?
Poul-Henning
>It's not that we can't tell the difference; we just can't forecast the
>difference.
In message <[EMAIL PROTECTED]>, Mike S writes
:
>At 08:27 AM 7/14/2005, Poul-Henning Kamp wrote...
>
>>I find it surreal that astronomers cannot tell the difference
>>between precision time and the Earth rotational orientation.
>
>But then again, you've demonstrated yourself to be an idiot incapabl
Rob Seaman wrote:
> Hi,
>
> John Ackermann says:
>
>> By the way -- Rob's message was held as a non-member submission
>> which I approved. Unless he's subscribed to the list in the
>> meantime, he won't see any responses unless you separately cc him.
>
>
> Thanks for approving the message - it
Brooke,
True. However, the timescale in which Leap Hours are interesting is
also that in which 5 digit years are required, so those problems can
both be fixed by the COBOL programmers in the late 9990s. [humor]
GPS time is not a thing that astronomers want to use in the long run,
although th
Hi David:
My concern is that if the time between leaps gets to be long then there
will be another Y2K type problem. I.e. programmers will ignore the Leap
Hour, figuring that they will be dead when it occurs, and when it does
there will be many broken programs.
The GPS time scale does not ha
It's not that we can't tell the difference; we just can't forecast the
difference.
-Original Message-
I find it surreal that astronomers cannot tell the difference
between precision time and the Earth rotational orientation.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
[EMAIL
At 08:27 AM 7/14/2005, Poul-Henning Kamp wrote...
>I find it surreal that astronomers cannot tell the difference
>between precision time and the Earth rotational orientation.
But then again, you've demonstrated yourself to be an idiot incapable of
rational argument. What is surreal is that peopl
By the way -- Rob's message was held as a non-member submission which I
approved. Unless he's subscribed to the list in the meantime, he won't
see any responses unless you separately cc him.
John
Poul-Henning Kamp wrote:
>In message <[EMAIL PROTECTED]>, Rob Seaman writes:
>
>
>
>>I find
In message <[EMAIL PROTECTED]>, Rob Seaman writes:
>I find it surreal that it is the precision timing community who are
>arguing that the public have no need for access to precision time.
Normal people need (precision) time.
Astronomers need Earth rotational orientation.
I find it surreal tha
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