Comments on http://www.w3.org/TR/timezone/ of 13 October 2005

Thank you for this WG Note, to which Frans Englich recently called my
attention.  It is very helpful.

I have some comments.

(1) In section 1.2 "Identifying Time Zones and Zone Offsets", you write:

   As mentioned before, XML Schema only supports zone offsets ...
   So a wall time expressed as an XML Schema time value, must
   choose which zone offset to use.

This is true as far as it goes.  But unless I am missing something
crucial, it is a property not only of XML Schema but of every system
that uses ISO 8601 notation for dates and times.  As you point out
earlier in section 1.2, ISO 8601 representations can use time zone
offsets; unless I am missing something in my review of ISO 8601,  
however,
they do not provide for the use of representations of time zones, as
you define the term.

Perhaps I am over-sensitive here, but the passage quoted above seems to
me to be attributing XSD's reliance on time zone offsets (and the
difficulties that entails for descriptions of wall clock time) to a
decision made by the designers of XSD not to support time zones,
instead of to the decision made by the designers of XSD to support
ISO 8601 as the relevant international standard, and to achieve
compatibility with the timestamp datatypes of SQL.

I think the passage would be less misleading if it read "As mentioned
before, ISO 8601 and XML Schema only support ...".

(2) The passage quoted also seems, in the phrase "choose which zone
offset to use", to overlook the possibility of representing such
wall-clock times with structures like an offset-free xsd:time value
in one attribute or element and a code for the time zone (e.g. PT
or America/Los_Angeles or ...) in another.

(3) in section 1.4.1, the phrase

     a meeting that is always UTC-08:00 (and thus at 7:00 in the
     morning in Pacific time during parts of the year)

seems unclear to this reader.  What does it mean for a meeting to
"be UTC-08:00"?  I think you mean "a meeting that is always
scheduled for 08:00-08:00", but only you can say for certain.

Received on Monday, 4 August 2008 23:45:09 UTC