On 20 Aug 2004 18:10:04 GMT, are (Acrosticus)
wrote:

From: (Mark Brader)
Date: 15/08/2004 19:32 GMT Daylight Time
Message-id:

Aidan Stanger writes:
Dr John Stockton wrote:

JRS: In article , dated
Thu, 12 Aug 2004 16:12:29, seen in news:uk.transport.london, Acrosticus
posted :
From: Stuart
Date: 11/08/2004 09:58 GMT Daylight Time

No such thing.

....Skip the lies bit.

Thanks for that! It does know the name of the time zone though, which for half
the year is Greenwich Mean Time but at the moment it's British Summer Time (ie
GMT plus 1 hour); which it calls "GMT Daylight Time" for some reason of its
own.

Bit of a shame that someone with "Dr" in front of their name should be so
pedantic and ignorant at the same time though isn't it?

Any real pedant would know that in the vicinity of the zero meridian
we stopped using GMT - based on astronomical time in 1972 and switched
(after failing to agree the defining language for its TLA with the
French) to UTC - based on atomic time. UTC gets kept in sync with the
earths rotation by the occasional insertion of leap seconds which were
not required with the older time scale.

Should bus timetables compensate for leap seconds? (A pedantic attempt
to stay on topic)

--
Peter Sumner

JRS: In article , dated
Fri, 20 Aug 2004 18:10:04, seen in news:uk.transport.london, Acrosticus
posted :
From: (Mark Brader)
Date: 15/08/2004 19:32 GMT Daylight Time
Message-id:

Aidan Stanger writes:
Dr John Stockton wrote:

JRS: In article , dated
Thu, 12 Aug 2004 16:12:29, seen in news:uk.transport.london, Acrosticus
posted :
From: Stuart
Date: 11/08/2004 09:58 GMT Daylight Time

No such thing.

Not only is there no such thing, Acrosticus's claim that Stuart had
posted that was a lie! ...

We don't have to throw around words like "lie"; his software is probably
rendering all Date: lines converted to his local time zone (which it
obviously doesn't know the name of), and he copied what he saw.

Thanks for that! It does know the name of the time zone though, which for half
the year is Greenwich Mean Time but at the moment it's British Summer Time (ie
GMT plus 1 hour); which it calls "GMT Daylight Time" for some reason of its
own.

In other words, "no such thing".

Stuart's headers include such as "Date: Thu, 12 Aug 2004 09:59:54
+0100".

There's nothing there to show that the poster is in the UK; that offset
is compatible, for example, with Lagos, where Summer Time is not needed.

The software used by Acrosticus is incompetently configured, and its
user has failed to correct it.

--
© John Stockton, Surrey, UK. Turnpike v4.00 MIME. ©
Web URL:http://www.merlyn.demon.co.uk/ - FAQish topics, acronyms, & links.
Check boilerplate spelling -- error is a public sign of incompetence.
Never fully trust an article from a poster who gives no full real name.

In message , at 10:27:07 on
Sat, 21 Aug 2004, Peter Sumner
remarked:
Any real pedant would know that in the vicinity of the zero meridian
we stopped using GMT - based on astronomical time in 1972 and switched
(after failing to agree the defining language for its TLA with the
French) to UTC - based on atomic time.

Depends who "we" are. It would seem that official time as defined by UK
legislation is still GMT (aka UT1).

See Hansard for the debate on the failed "Co-ordinated Universal Time
Bill" in 1997.
--
Roland Perry

On Sat, 21 Aug 2004 14:10:11 +0100, Roland Perry
wrote:

In message , at 10:27:07 on
Sat, 21 Aug 2004, Peter Sumner
remarked:
Any real pedant would know that in the vicinity of the zero meridian
we stopped using GMT - based on astronomical time in 1972 and switched
(after failing to agree the defining language for its TLA with the
French) to UTC - based on atomic time.

Depends who "we" are. It would seem that official time as defined by UK
legislation is still GMT (aka UT1).

The official time in the UK is maintained by the NPL and it ticks
atomic seconds in UTC. This is what happens in practice as you can
tell by the addition of leap seconds, which show plainly as an extra
'pip' in the time signals. If we were using GMT these leap seconds
would not be required. For pedants there is a good explanation at
http://www.npl.co.uk/time/leap_second.html.

Our legislators have mistakenly ignored this and still pretend that
GMT is in use. Not that the maximum error of 0.9 sec makes much
difference to the man on the Clapham omnibus



--
Peter Sumner

In message , at 17:28:52 on
Sat, 21 Aug 2004, Peter Sumner
remarked:
The official time in the UK is maintained by the NPL and it ticks
atomic seconds in UTC.

This is *a* time that is maintained by the NPL.

This is what happens in practice as you can tell by the addition of
leap seconds, which show plainly as an extra 'pip' in the time signals.
If we were using GMT these leap seconds would not be required. For
pedants there is a good explanation at
http://www.npl.co.uk/time/leap_second.html.

And even more detail at:

http://www.wordiq.com/definition/Universal_Time:

Our legislators have mistakenly ignored this and still pretend that
GMT is in use.

Whether a mistake or not, the fact they have ignored the need to make a
change means that Official Time is still UT1.

Not that the maximum error of 0.9 sec makes much difference to the man
on the Clapham omnibus

We can at least agree that 0.9sec is the biggest difference between the
various times.
--
Roland Perry

JRS: In article , dated
Sat, 21 Aug 2004 10:27:07, seen in news:uk.transport.london, Peter
Sumner posted :

Any real pedant would know that in the vicinity of the zero meridian
we stopped using GMT - based on astronomical time in 1972 and switched
(after failing to agree the defining language for its TLA with the
French) to UTC - based on atomic time.

"We" does not include the UK, where legal time remains GMT-based, use of
UTC time-signals notwithstanding.

Presumably, therefore, you live in France, Spain (UTC-based, I think),
Algeria, Mali, Burkina Faso, Ghana, or Togo. Or afloat. Or in Sanae.

BTW, UTC is based on astronomical time; that is what Leap Seconds are
for. Only the scale of seconds is atomic-based.

The correct TLAs for the times of almost all of the UK are GMT and BST.

How, in general, does UK transport deal with services operating across
and around 01:00 GMT on the last Sunday of March and of October?

--
© John Stockton, Surrey, UK. Turnpike v4.00 MIME. ©
Web URL:http://www.merlyn.demon.co.uk/ - w. FAQish topics, links, acronyms
PAS EXE etc : URL:http://www.merlyn.demon.co.uk/programs/ - see 00index.htm
Dates - miscdate.htm moredate.htm js-dates.htm pas-time.htm critdate.htm etc.

On Sat, 21 Aug 2004 20:02:03 +0100, Dr John Stockton
wrote:

JRS: In article , dated
Sat, 21 Aug 2004 10:27:07, seen in news:uk.transport.london, Peter
Sumner posted :

Any real pedant would know that in the vicinity of the zero meridian
we stopped using GMT - based on astronomical time in 1972 and switched
(after failing to agree the defining language for its TLA with the
French) to UTC - based on atomic time.

"We" does not include the UK, where legal time remains GMT-based, use of
UTC time-signals notwithstanding.

Do we agree that the civil time used in the UK is UTC and that
legislation has failed to keep up with this?

Presumably, therefore, you live in France, Spain (UTC-based, I think),
Algeria, Mali, Burkina Faso, Ghana, or Togo. Or afloat. Or in Sanae.

I'll admit to being where my posting address paces me - in the UK

BTW, UTC is based on astronomical time; that is what Leap Seconds are
for. Only the scale of seconds is atomic-based.

Agreed, though for that reason I would say that UTC is based on an
atomic scale and corrected to astronomical time - like the NPL
http://www.npl.co.uk/time/time_scales.html#World

The correct TLAs for the times of almost all of the UK are GMT and BST.

Agree with BST, but not GMT. Referring to the time zone links from
your pages http://www.cl.cam.ac.uk/~mgk25/iso-time.html#zone says
that the term should no longer be used and
http://www.lib.utexas.edu/maps/world_maps/time_zone_world_98.jpg
refers to the zero meridian time zone as UTC formerly GMT.

Fascinated by why you say almost all of the UK. Is there some part in
a different time zone?

How, in general, does UK transport deal with services operating across
and around 01:00 GMT on the last Sunday of March and of October?

A much more realistic question than asking how leap seconds are coped
with.
--
Peter Sumner

On Sat, 21 Aug 2004 19:25:01 +0100, Roland Perry
wrote:

In message , at 17:28:52 on
Sat, 21 Aug 2004, Peter Sumner
remarked:
The official time in the UK is maintained by the NPL and it ticks
atomic seconds in UTC.

This is *a* time that is maintained by the NPL.

NPL say http://www.npl.co.uk/time/ "Home of the nation's atomic time
scale" and "providing the UK time scale related to UTC ", in both
cases its "the" time scale rather than just "a" time.

--
Peter Sumner

In message , at 11:32:43 on
Sun, 22 Aug 2004, Peter Sumner
remarked:
NPL say http://www.npl.co.uk/time/ "Home of the nation's atomic time
scale" and "providing the UK time scale related to UTC ", in both
cases its "the" time scale rather than just "a" time.

But go on to say:

"Universal Time (UT) now has three separate definitions (UT0,
UT1, UT2) depending on which corrections have been applied to
the Earth's motion. Authorities are not agreed on whether GMT
equates with UT0 or UT1, however the differences between the two
are of the order of thousandths of a second.

Meanwhile, they are wrong to imply that UTC is the legally accepted
time; unless someone has deliberately "dumbed down", for their Homepage,
the choice between UT0/UT1 and called that UTC.

--
Roland Perry

JRS: In article , dated
Sun, 22 Aug 2004 11:17:41, seen in news:uk.transport.london, Peter
Sumner posted :
On Sat, 21 Aug 2004 20:02:03 +0100, Dr John Stockton
wrote:

JRS: In article , dated
Sat, 21 Aug 2004 10:27:07, seen in news:uk.transport.london, Peter
Sumner posted :

Any real pedant would know that in the vicinity of the zero meridian
we stopped using GMT - based on astronomical time in 1972 and switched
(after failing to agree the defining language for its TLA with the
French) to UTC - based on atomic time.

"We" does not include the UK, where legal time remains GMT-based, use of
UTC time-signals notwithstanding.

Do we agree that the civil time used in the UK is UTC and that
legislation has failed to keep up with this?

Yes, and no. UK civil time is GMT, but law enforcement has been lax.

Fascinated by why you say almost all of the UK. Is there some part in
a different time zone?

There is some part which, I have been told by one who should know, keeps
a time differing significantly from London Time. I doubt whether it
should be described as a zone.

--
© John Stockton, Surrey, UK. Turnpike v4.00 MIME. ©
Web URL:http://www.merlyn.demon.co.uk/ - FAQqish topics, acronyms & links;
some Astro stuff via astro.htm, gravity0.htm; quotes.htm; pascal.htm; &c, &c.
No Encoding. Quotes before replies. Snip well. Write clearly. Don't Mail News.