Comment: issues with owl time

Many applications use the TZ timezone database 
(http://www.twinsun.com/tz/tz-link.htm). Is there a mapping between TZ 
timezones and the timezones from the www.w3.org/2006/timezone-world or 
www.w3.org/2006/timezone-us?

The DurationDescription class doesn't support negative durations
(as the XSD duration datatype does). Such negatve durations come up in 
iCal files. (That's why using a DurationDescription to represent an ical 
Duration would need some additional information if it's negative)

The timeZoneProperty of the owl-time ontology points to a timezone, not
to a Region. Doesn't it imply loss of information? It would be nice to 
be able to attach a DateTimeDescription to a geographical region.

Antoni Mylka
antoni.mylka@dfki.uni-kl.de