[caldeveloper-l] DTSTART that doesn't match RRULE pattern

[Ken Murchison]

All,

At the recent CalConnect in Karlsruhe, we had a discussion about whether 
a DTSTART that doesn't match the RRULE pattern should be included in the 
recurrence set, and if so, should the non-matching DTSTART be accounted 
for by the COUNT part in the RRULE.  We were looking to get consensus so 
we could file a clarifying errata against RFC 5545.  We would also like 
to have the new JSCalendar format be more concrete on the topic.

Opinions in the room were pretty close to 50/50, so we decided it was 
best to ask for opinions from the community at large.  So here's your 
chance to speak up, either with your personal opinion and/or about your 
knowledge of how current implementations handle this.


My personal opinion is that if DTSTART doesn't match the RRULE, it 
should NOT be included in the recurrence set and obviously NOT accounted 
for by COUNT.  Some may argue that such a DTSTART should be treated like 
an RDATE, but we already have RDATE, so use it and fix DTSTART to match 
the RRULE.  That said, I don't really care what theh consensus is, just 
that we document it so that all current and future apps to the same thing.

-- 
Ken Murchison
Cyrus Development Team
FastMail US LLC