[Ietf-calsify] summary of jabber sessions and confirmation of issues
reinhold at kainhofer.com
Wed Oct 11 09:16:24 PDT 2006
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Am Mittwoch, 11. Oktober 2006 18:03 schrieben Sie:
> Hi Reinhold,
> --On October 11, 2006 5:50:22 PM +0200 Reinhold Kainhofer
> <reinhold at kainhofer.com> wrote:
> >> An instance representing the supplied DTSTART value is always present as
> >> per 126.96.36.199 (which says in the Description paragraph: 'The "DTSTART"
> >> property defines the first instance in the recurrence set.'). So a
> >> COUNT=1 will only ever generate the DTSTART instance. So your
> >> 'intuitive' expectation is wrong.
> > On the other hand, section 188.8.131.52 about EXRULE (and section 184.108.40.206
> > about EXDATE) says that the EXRULE/EXDATE properties can be used to
> > exlude the DTSTART. Notice the word *can* and "in such cases", which
> > indicate that the DTSTART is not always automatically generated by an
> > EXRULE.
> > So, the DTSTART is not always the first instance in the recurrence set,
> > and an EXRULE does not necessarily exclude the DTSTART. Consequently, a
> > recurrence rule does not necessarily generate the DTSTART as its first
> > date/time.
> But again, 220.127.116.11 states: 'The "DTSTART" defines the first instance in the
> recurrence set.'. I consider that a stronger statement than 'can be used to
> exlcude...'. As defined it 'always excludes the DTSTART'.
Well, first, there is that "if specified", which I understand as "if generated
by the rule". And second, if DTSTART is excluded by EXRULE or EXDATE it is
not the first instance in the recurrence set, so we have a contradiction in
> The bottom line is this just re-emphasizes why EXRULE is a real problem and
> should be deprecated.
The same problem goes with RRULE and the COUNT.
Reinhold Kainhofer, Vienna University of Technology, Austria
email: reinhold at kainhofer.com, http://reinhold.kainhofer.com/
* Financial and Actuarial Mathematics, TU Wien, http://www.fam.tuwien.ac.at/
* K Desktop Environment, http://www.kde.org, KOrganizer maintainer
* Chorvereinigung "Jung-Wien", http://www.jung-wien.at/
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