Re: Comment: issues with owl time

Hi Antoni,

Thank you for your comments.

> 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?

No, currenly there is no mapping between them, but it would be useful
to explore that.

> 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)

Thank you for pointing that out. I think the negative durations are only 
used for subtractions in temporal arithmetic. For those cases, subtraction 
rules can be applied to the positive durations.

> 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.

It seems when we use time zones for dateTimes, we are most interested in 
which time zone it is in and how much time offset from GMT/UTC. For 
example, XSD:dateTime only has the duration offset from UTC for time 
zones.

Thanks,

Feng

--
Feng Pan, Ph.D. Candidate
USC Information Sciences Institute (ISI)
Email: pan@isi.edu
Web: http://www.isi.edu/~pan/