(W-22) RE: Timezones and Olson Tables

[Doug Royer <Doug.Royer@xxxxxxx>]

> From: "IANA" <iana@ISI.EDU>
> Date: Wed, 28 Jul 1999 11:26:19 -0700
> 
>    (per Pat Egen) Keith wrote (in part):
>     - - - - - -
>
>     1. we need to make sure that everyone, including Olson, understands
>       and agrees on issues like copyright ownership, distribution rules
>       (presumably free to everyone), and change control

I have sent email to the ~owner~ of that database and Cc'd Pat Egen.
We will keep the WG informed of the status of the WG request to use
their data.

I believe that its free to all right now. I can not find a copyright
notice in any of the data. The 'sample code' has:

 Copyright (c) 1985, 1987, 1988 The Regents of the University of California.

However it is not the sample code that we would be using.

>     2. I think calsch should attempt to establish globally-scoped
>       timezone names, probably using different (or alternate) names
>       to those used in the Olson database.  If I understand correctly
>       Olson prefers to associate timezones with the names of continents
>       and nearby cities; but since most timezones are set by political
>       jurisdictions I suspect that we will get more precision (and the
>       timezones will be more "obvious") if we name the timezones after
>       the political regions for which those timezones are established.
>       So I would recommend that primary timezone names be: country code
>       for the top level of timezone name, followed by subdivisions
>       (for those few countries for which it is necessary), followed
>       very occasionally by ad hoc divisions when these are necessary.
>       E.g. /NO (for time in Norway) and /US/Eastern or /US/Indiana
>       (for time in Eastern US (EST/EDT) or the portion of Indiana
>       that always uses CST.  Note that the requirements for calsch
>       timezone names (which are mostly used to indicate events in the
>       future) may be different than those for the traditional uses of
>       the Olson database (which oddly enough are mostly used to
>       indicate events in the past - e.g. file modification times).

The Olson database address this issue by allowing 'aliases'.
For example US/Pacific is one name for a timezone. Because
'PST' is unsed more than once in the world. Thus 'PST' is not
in the database.

It might be easier if we just translate the data. There are a large
number of names for the same timezone.

As to future vs. past data. The Olson database tracks timezones
into the past. However it also seems to be up to date and is
valid for future information.

We might want to add Timezone aliases to iCalendar to address
these same issues.

>       Of course not all timezones are set by countries, so we would
>       still need a way to register other kinds of timezones.
>       Ideally countries could eventually get direct change control
>       over their timezone records at IANA.

That's the fun part :-)

>     - - - -
>     Ok list, comments, suggestions.  Doug, I know you have been working on
> this a lot.  Your thoughts?

-Doug
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