New Mail List - timezones.external at software.com

[Markus Kuhn]

Doug Royer <doug at home.royer.com>:
> There are three goals of this list.
> 
> 	1) Port the government database and 'zic' (Zone Information Compiler)
> 	   to other OS's and have it also provide the data in VTIMEZONE
> 	   format. Most UNIX's use the government database format and the zic
> 	   compiler (man zic).
> 
> 	2) Convert the government database into VTIMEZONE records for IANA
> 	   to administer.
> 
> 	3) Give away the results to the public domain.

There might be a few misunderstandings involved here. First, there is no
"government timezone database". What you see on ftp://elsie.nci.nih.gov/pub/
is the collaboration of a number of volunteers (Arthur Olson, Paul
Eggert, et al.), the result of which is commonly referred to as the
public domain "Olson database". The only relation to the US government
is that the group has been using an ftp server of the National Cancer
Institute, which happens to be located in the .gov domain.

There exists already a well-established mailing list for discussions
on time zones and the maintenance of the Olson database, namely

  tz at elsie.nci.nih.gov

Contact

  tz-request at elsie.nci.nih.go

to join the club.

Since there is a lot of accumulated expertise on this mailing list,
handing over the administration of the database to IANA seems to be a
rather dubious buerocratic effort. Who at IANA would take over authority
over the database and is really comparably qualified to the current
contributors of the Olson database who have done a splendid job for
the last 15 years?

Please understand that IANA is a registration service, while what the
group around Olson is doing is more a detective service that observes
and documents the highly complicated world of national and regional
decisions about time-zone changes in the world. If government X is going
to change its local time zone, it is more likely that the database
maintainer will hear about this from various informers or media reports
around the world, as well as resources such as IATA or CIA. It is much
less likely that the respective countries will report timezone changes
directly to IANA officially. A detective service can provide a more
accurate representation of the real world than a registration service.

Just dropping the maintenance of the time zone database into the
responsibility of IANA might give them a task they underestimate at the
moment.

If you don't like the current zic format, feel free to add a zic->
VTIMEZONE format converter to the Olson package. Looks mostly like a
bijective transform to me, except that the zic input files contain a lot
of valuable comments that identify official reference documents.

Only if the output of that converter on the regular updates of the Olson
package turns out to be unsatisfactory, I would start worrying about
setting up a parallel bureaucracy and an independent database. I see
really no need for yet another mailing list.

> RFC-2445 defines VTIMEZONE.

     BEGIN:VTIMEZONE
     TZID:US--Fictitious-Eastern
     LAST-MODIFIED:19870101T000000Z
     BEGIN:STANDARD
     DTSTART:19671029T020000
     RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10
     TZOFFSETFROM:-0400
     TZOFFSETTO:-0500
     TZNAME:EST
     END:STANDARD
     BEGIN:DAYLIGHT
     DTSTART:19870405T020000
     RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=4;UNTIL=19980404T070000Z
     TZOFFSETFROM:-0500
     TZOFFSETTO:-0400
     TZNAME:EDT
     END:DAYLIGHT
     BEGIN:DAYLIGHT
     DTSTART:19990424T020000
     RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=4
     TZOFFSETFROM:-0500
     TZOFFSETTO:-0400
     TZNAME:EDT
     END:DAYLIGHT
     END:VTIMEZONE

If people really think that this looks that much nicer or easier to
parse for machines and humans ...

Markus

-- 
Markus G. Kuhn, Computer Laboratory, University of Cambridge, UK
Email: mkuhn at acm.org,  WWW: <http://www.cl.cam.ac.uk/~mgk25/>