RDF calendar dates, interpretation properties and datatypes

hi all,

I have an action to send a mail about intepretation types and datatypes
for timezones:

http://rdfig.xmlhack.com/2003/07/30/2003-07-30.html#1059578029.477714

Here is is....

We have a couple of questions to be answered:
- is the way we handle dates, dateTimes and timezones ok at the moment?
- if it isn't, what's the best way?

In RDF Cal (http://www.w3.org/2002/12/cal)

we attach timezones to properties like this:
<Vevent>
 <dtstart rdf:parseType="Resource">
  <dateTime>2003-01-15T18:00:00</dateTime>
  <tzid>/softwarestudio.org/Olson_20011030_5/Europe/London</tzid>
 </dtstart>
</Vevent>

but then if we say

<Vevent>
 <dtstart rdf:parseType="Resource">
  <dateTime>2003-01-15T18:00:00</dateTime>
  <tzid>/softwarestudio.org/Olson_20011030_5/Europe/London</tzid>
  <dateTime>2003-01-15T19:00:00</dateTime>
  <tzid>/softwarestudio.org/Olson_20011030_5/Europe/Paris</tzid>
 </dtstart>
</Vevent>

then the timezones and dates get mixed up together.

This is explained here:
http://esw.w3.org/topic/InterpretationProperties; I've repeated it here
in XML/RDF because I read it better.

So I think that an interpretation property in this case is something
like

<Vevent>
 <dtstart>
  <DateTime>
   <value>2003-01-15T18:00:00</value>
   <tzid>/softwarestudio.org/Olson_20011030_5/Europe/London</tzid>
  </DateTime>
 </dtstart>
 <dtstart>
  <DateTime>
   <value>2003-01-15T17:00:00</value>
   <tzid>/softwarestudio.org/Olson_20011030_5/Europe/Paris</tzid>
  </DateTime>
 </dtstart>
</Vevent>

(i.e. making the DateTime a class not a property. Is that right?)

So, is this a place to use XSD datatypes in RDF?
using the example from
http://www.w3.org/2001/sw/RDFCore/TR/WD-rdf-primer-20030117/Overview.html#example21
(thanks Dave)

<Vevent>
 <dtstart>
  <DateTime>
    <rdf:value
rdf:datatype="http://www.w3.org/2001/XMLSchema#dateTime">2003-01-15T18:00:00</rdf:value>
    <tzid>/softwarestudio.org/Olson_20011030_5/Europe/London</tzid>
  </DateTime>
 </dtstart>
</Vevent>

what do people think?

cheers

Libby

Received on Tuesday, 19 August 2003 12:16:48 UTC