Re: [calsify] SKIP was Re: AD review of draft-ietf-calext-rscale-03

[Ken Murchison <[e-mail]>]

On 02/03/2015 03:48 PM, Cyrus Daboo wrote:
> Hi Ken,
>
> --On February 3, 2015 at 3:23:13 PM -0500 Ken Murchison 
> <[e-mail]> wrote:
>
>> I think both of these come out the same (and my libical computes the
>> same) as there is no BYMONTHDAY or anything else forcing the expansion
>> onto Feb 29 in a non-leap year.  In this case the DTSTART just gives us
>> the first instance (which in this case doesn't fall on a Sunday so isn't
>> included).  After that, the BYMONTH+BYDAY is what really drives the
>> expansion.
>
> But if we use 20140229 as the DTSTART - and that is a leap day on a 
> Sunday - then I think Marten is write that apply the SKIP after the 
> BYMONTH and before the BYDAY would result in only Sundays in leap 
> years being returned.
>
> I think having those two rules return different results would be 
> counterintuitive so I would prefer we left the order of BYxxx element 
> and SKIP processing as it is now.

What I was thinking, and probably wasn't clear, is that we apply SKIP to 
the month after BYMONTH and apply SKIP to the day after BYMONTHDAY/BYDAY.

I don't think we want any of the down stream rule parts to be operating 
on a bogus month.

-- 
Kenneth Murchison
Principal Systems Software Engineer
Carnegie Mellon University