[SLO-TIME] Greenwich Electronic Time (GeT) - NTP Request
Mark Martinec
Mark.Martinec@ijs.si
Mon, 02 Oct 2000 17:55:13 +0200
Prilagam svoj javni odgovor na posto, ki smo jo dobili
pred casom administratorji javnih NTP streznikov od IMRG/GeT.
Morda bo za koga zanimivo branje, zanimivo pa je tudi
branje na http://www.egroups.com/message/ISO8601/76 .
Pozdrav
Mark
--
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!! Mark Martinec (system manager) tel +386 1 4773-575 !!
!! J. Stefan Institute, Jamova 39 fax +386 1 2519-385 !!
!! SI-1000 Ljubljana, Slovenia mark.martinec@ijs.si !!
!!!!!!!!!!!!!!!!!!!!!!!!!! http://www.ijs.si/people/mark/ !!!!
--------------------------------------------------------------------------------
| Date: Wed, 06 Sep 2000 16:14:55 +0100
| From: Gareth Donovan <gareth@imrg.org>
| Subject: Greenwich Electronic Time - NTP Request
| Dear NTP service provider,
| I am the Project Development Manager with the Interactive Media in Retail
| Group (http://www.imrg.org), which is leading the Greenwich Electronic
| Time initiative (http://www.get-time.org) =96 an industry led project
| launched on the 1st January 2000 by Tony Blair, the UK Prime Minister.
| [...]
Hi Gareth (and others),
Since your mail message was sent to several (most?) time keepers
from the list of public NTP servers, I thought it would not
be too inappropriate to CC my reply to the comp.protocols.time.ntp
newsgroup (and ISO8601@egroups.com) and perhaps stir some discussion there.
_After_ writing the following reply, I noticed the posting on the
mailing list ISO8601@egroups.com from Ian Galpin, dated 2000-09-14,
on the same subject:
http://www.egroups.com/message/ISO8601/76
which basically says the same as I do below. Although this now makes
my reply a bit redundant, it does not hurt to say it twice
in different words.
| [...]
| We are currently bringing together a network of accurate public NTP
| servers to provide a simple method for internet users to benefit from
| synchronizing their system clocks to UTC.
|
| I am writing to ask your permission in principal to include your NTP
| servers in the GeT Network, alongside our sponsors and other interested
| organizations systems.
|
| Through a generic DNS scheme based on ISO 3166 country codes and some
| sub-divisions for larger territories, we will link users to their
| closest NTP source. [...]
| [...]
| accurate, however the lack of knowledge and understanding of the
| necessity for accuracy amongst the public and more importantly, many
| businesses, will become an issue as the networked economy
| and e-commerce continue to grow in importance.
|
| GeT aims to promote this issue and provide a trusted route to free tools
| and information for both business and the public.
I have mixed feelings about the GeT project. I am aware of its
existence since the spring of this year when I was compiling
a set of links to time-related information on the web for my
NTP page at http://www.ijs.si/time/ -- and decided at that time
_NOT_ to include a link to your project in my document.
I welcome your efforts to promote the awareness of the importance
of accurate time for e-business and other users, and I congratulate
you managed to provide three reference time servers at LINX internet
exchange, with the support from the National Physical Laboratory.
I also think the choice of NTP for time dissemination
across the internet was a good choice (no real rivals there!).
What I don't consider a good idea is the confusion you make
about the reference time. Although your claimed intention
is to reduce confusion, you actually add to it
by promoting a 'GMT' time, and even worse, a 'GeT' time
when the legal basis for civil time worldwide is UTC.
GMT can have two interpretations:
- traditionally the Greenwich Mean Time is a time scale based on the
apparent motion of the "mean" sun with respect to the zero degrees meridian;
this is in fact the UT1 astronomical time scale;
- it can also be understood to be a synonym for UTC, as you have chosen.
The difference between the two can be up to 0.9 seconds.
Negligible? A lot? Depends on your point of view and expectations.
Even in your web page http://www.get-time.org/ you have to explain
what is your interpretation of GMT - do you expect to be easier
to use GMT and explain every time that you actually mean UTC
in this context, or would it be easier to just use UTC,
as most of the world-wide legislations on civil time now use?
Here is an excerpt from
http://ecco.bsee.swin.edu.au/chronos/GMT-explained.html
In 1928, when the term Universal Time was introduced, variations in the
earth's spin were not yet known. So the term GMT was, in essence,
replaced by UT1. Despite the official adoption of the term UT, the
navigational publications of English-speaking countries retained the
term GMT as a synonym for UT1 for some time. So, even today, in
astronavigation, GMT can imply UT1. But in general usage (including
that of shortwave broadcasters such as the BBC, for example), GMT
now usually means the civil (atomic-second-based) time kept in the
United Kingdom which is the standard time of the time zone centred on
the 0 degree meridian. In this (the most common) usage, the terms GMT
and UTC are identical. But because there are two possible meanings for
-------------------------------------------
GMT differing by up to 0.9 seconds, the term GMT should not be used
--- --------------------===--------
for precise purposes -- particularly not in reference to GPS observations!
----================
In http://www.get-time.org/ => Thinking Time => Avoiding Business Chaos
you go even further and introduce a parallel time baseline
called GeT, presenting it in such a way that it can easily be
understood to mean something different than UTC:
GeT: The natural companion to GMT
The availability of a parallel E-Time baseline that maps
and is understandable in relation to the existing time
baseline has a natural market, business and consumer
advantage. Simple tools can track and map physical to
E-time and make commitments to consumers. The ability to
set a user expectation globally in relation to service
commitment and fulfillment is essential. Days as a measure
of service commitment can be eliminated when service is
measured against GeT in hours "Thank you for your order.
It will be dispatched at X Hour GeT (XX.YY Supplier Local
Time) and is scheduled to be with You at (ZZ.WW Consumer
Local time) GeT + Y hours.) By normalizing the time you
remove the need for consumers to calculate, understand
time differences and provide them a single term of
reference for service measure.
Now in addition to the GMT ambiguity, each company using your
concepts would have to educate their customers (including common
everyday people) what GeT means.
Enough bashing - and a little sidetrack: I think your
programme would be a nice vehicle to promote the use of the
ISO 8601 International Date Format (but explicitly not its
two-digit year variant). It would be a great relief in the
business correspondence to avoid dates like 10/02/01
with its 6 possible interpretations, but to see e.g. 2001-10-02 instead.
(see http://www.cl.cam.ac.uk/~mgk25/iso-time.html ,
http://www.saqqara.demon.co.uk/datefmt.htm
and http://www.egroups.com/subscribe/ISO8601 ,
in particular http://www.egroups.com/message/ISO8601/76 ).
I do not claim ISO 8601 is flawless, but is the best we have so far.
Two quotations from http://www.cl.cam.ac.uk/~mgk25/iso-time.html :
Chicago Manual of Style now recommends using the international
standard time notation in publications.
[...]
In May 1996, the German standard DIN 5008, which specifies
typographical rules for German texts written on typewriters, has been
updated. The old German numeric date notations DD.MM.YYYY and
DD.MM.YY have been replaced by the ISO date notations
YYYY-MM-DD and YY-MM-DD. Similarly, the old German time
notations hh.mm and hh.mm.ss have been replaced by the ISO
notations hh:mm and hh:mm:ss. Those new notations are now also
mentioned in the latest edition of the Duden. The German
alphanumeric date notation continues to be for example "3. August
1994" or "3. Aug. 1994". The corresponding Austrian standard has
already used the ISO 8601 date and time notations before.
ISO 8601 has been adopted as European Standard EN 28601 and is
therefore now a valid standard in all EU countries and all conflicting
national standards have been changed accordingly.
Now back to your original question:
| I am writing to ask your permission in principal to include your NTP
| servers in the GeT Network, alongside our sponsors and other interested
| organisations systems.
In principle you have my permission as long as you make it understood
to your clients (or somehow enforced automatically) that our NTP server(s)
can be used under the same conditions under which they are listed in the
David Mills' list of public servers. In particular I wouldn't want
to see the end-users' desktop PCs to directly try to obtain their time
from our public NTP servers. I don't object to the company's main
time servers to sync to our NTP serves though. I also don't like
misconfigured PCs banging on out firewall trying to access our
time server using other protocols than NTP, such as Time Protocol (RFC868)
or Daytime Protocol (RFC867).
The other condition is that I don't allow our company (institute) name
or my personal name to be used as an endorsement of, or to promote GeT, or
any company using it, or any product made by such a company, by IMRG or GeT.
Best regards
Mark Martinec (timekeeper@ijs.si)
--
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!! Mark Martinec (system manager) tel +386 1 4773-575 !!
!! J. Stefan Institute, Jamova 39 fax +386 1 2519-385 !!
!! SI-1000 Ljubljana, Slovenia mark.martinec@ijs.si !!
!!!!!!!!!!!!!!!!!!!!!!!!!! http://www.ijs.si/people/mark/ !!!!