TZ Data to XML Project

Paul Eggert eggert at
Thu Mar 8 01:24:49 UTC 2001

> From: "Chris Sells" <csells at>
> Date: Wed, 7 Mar 2001 15:46:42 -0800
> These are the outputs of my attempts to translate the native tz data into
> XML for easier parsing for applications other than implementations of the
> standard C routines related to time [1].

> [1]

Thanks.  I couldn't find a DTD or schema for the XML you generate but
I guess it's pretty easy to figure it out.  But this brings up an
important point: what should the DTD be?

I know of one other effort to XMLize time zone data, namely, the
effort to XMLize iCalendar.  Wouldn't it make sense for us to base a
tz DTD on that work?  (For more about iCalendar, please see

Some background: my impression is that XML is a bit of a hot potato
among the iCalendar folks.  iCalendar's VTIMEZONE objects can easily
be expressed using XML, but iCalendar itself doesn't use XML (partly
because it predates XML).  There is some sentiment to move towards XML
but it hasn't happened yet and may never happen.  For more about the
politics involved, please see

If we want to use an XMLized VTIMEZONE, Tim Berners-Lee once talked
about building a Resource Description Framework (RDF) model for
iCalendar; see <>.  (RDF is W3C's
application of XML for the semantic web; see <>
for more.)  Berners-Lee thought it was a pretty good match; see
That might be a good way to do it.  It'd be a smaller project than
what Berners-Lee was thinking of, since it would deal only with the
minimum necessary to represent VTIMEZONE.

If we're more conservative and want to use a hand-XMLized VTIMEZONE
without RDF, then I would look at the work of Frank Dawson (of Lotus)
et al.  For example, iPlanet's calendar server supports an iCalendar
XML DTD draft described in
<>.  That
draft is a bit outdated now but it should be easy to adapt its DTD to
match the VTIMEZONEs of the current iCalendar spec.

While we're on the subject, Damon Chaplin of Ximian has written an
tz-to-VTIMEZONE converter.  Perhaps we can use that.  See:

(Hmm, maybe I should add some of this stuff to tz-link....)

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