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], 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
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
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 think
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 for all
Those of you on the LEAPSECS mailing list will aready have seen this,
but I think its worth a read -
http://www.startribune.com/stories/404/5508732.html
I'm responding to Rob and Mike in this email.
First, Rob said
And if your software reports eclipses later than 2007, it may need to
be
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, sitting
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 with
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 least.
Bill asked -
The initial message asserts that leap
seconds are harmful. The argument remains unfocused because the
nature of the harm has not been specified.
I'll give you a very concrete example of the harm of leap seconds. As
part of my interest in astronomy, I chase total solar eclipses.
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
ESTIMATE would not
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
Chris O'Byrne says:
I'll give you a very concrete example of the harm of leap seconds. As
part of my interest in astronomy, I chase total solar eclipses. I've
written a program that runs on your mobile phone to calculate when you
can expect to see the eclipse start and end from your location
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]
[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
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
: So here is my suggestion, and it is an amalgamation of ideas from
: various quarters. Civil time should be based on a quadratic formula
: involving TAI. In other words, civil time should track UT over the long
: term, and be allowed to drift against UT over the short term.
Well, the varying
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 1.2 seconds between those two points.
The kind of
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 EXACTLY 1.2
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,
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
___
time-nuts mailing list
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 got
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 seconds
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
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
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
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 eventually
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
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
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,
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 was
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 one
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], 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) Bill,
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
] [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], Bill
Hawk
ins writes:
Garbage is in the eye of the beholder.
Indeed
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
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 time
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
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 involving
Poul-Henning Kamp replies:
Shouldn't we explore the requirements and use cases before making
a change to the standard?
Absolutely, but shouldn't we look at more than astronomy while
doing so?
Are you under the impression that the folks pushing this proposal are
looking anywhere beyond
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?
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
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 wasn't clear from the list's
web
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 wasn't clear
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 incapable
of
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