Re: [Evolution] Evolution Bug Day, Take 2

[Damon Chaplin <damon ximian com>]

On Fri, 2001-08-24 at 23:14, Thomas O'Dowd wrote:
> On Fri, Aug 24, 2001 at 10:16:41PM -0400, Damon Chaplin wrote:
> >  o Outlook doesn't like some types of recurrence rules,
> >    e.g. it doesn't like the BYMONTHDAY part of:
> > RRULE FREQ=YEARLY;INTERVAL=1;BYDAY=SU;BYMONTHDAY=1,2,3,4,5,6,7;BYMONTH=4
> >
> >    We may be able to rewrite the rules in a different way, or in the
> >    worst case we can forget about recurrence rules and use specific
> >    dates. This is a bit of a pain to fix.
>
> Looks like this means the first Sunday in April every year which can
> be rewritten as:
>
> RRULE:FREQ=YEARLY;INTERVAL=1;BYDAY=1SU;BYMONTH=4

Yeah, I spotted that as well. That gets rid of a lot of the uses in our
VTIMEZONE data. But there are still ~30 uses of BYMONTHDAY like the
above (but not starting at 1). Maybe a few could be replaced with
BYDAY=-1SU, but I don't think there are many like that.

I think we only have 2 options to deal with this:

 1) split the RRULE into separate RRULEs for each of the days, e.g.

   RRULE FREQ=YEARLY;INTERVAL=1;BYDAY=SU;BYMONTHDAY=1;BYMONTH=4
   RRULE FREQ=YEARLY;INTERVAL=1;BYDAY=SU;BYMONTHDAY=2;BYMONTH=4
   RRULE FREQ=YEARLY;INTERVAL=1;BYDAY=SU;BYMONTHDAY=3;BYMONTH=4
   RRULE FREQ=YEARLY;INTERVAL=1;BYDAY=SU;BYMONTHDAY=4;BYMONTH=4
   RRULE FREQ=YEARLY;INTERVAL=1;BYDAY=SU;BYMONTHDAY=5;BYMONTH=4
   RRULE FREQ=YEARLY;INTERVAL=1;BYDAY=SU;BYMONTHDAY=6;BYMONTH=4
   RRULE FREQ=YEARLY;INTERVAL=1;BYDAY=SU;BYMONTHDAY=7;BYMONTH=4

 I'd have to check that Outlook accepts this. This is also obviously
 7 times slower, though we don't have to expand it very often.


 2) use RDATEs instead of RRULEs and expand up to a certain year,
    say 2037.

 This makes the VTIMEZONE quite a bit bigger, and means it is only
 valid up to 2037. But it is simpler and quicker.

Can anyone think of another way of fixing it?

Damon