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

[Gregory Yakushev <[e-mail]>]

On Thu Feb 05 2015 at 5:23:19 PM Barry Leiba <[e-mail]>
wrote:

> >> I do NOT think that we need to accompany this with any list of
> >> calendars.  Whoever implements a particular calendar needs to know how
> >> it works in order to generate the right SKIP values anyway.  So why
> >> not just say that, and forget about having to include the SKIPs?
> >
> > I am not convinced that there is one convention per calendar system that
> is
> > consistently used. In discussions I have had with others I got the
> > impression that the skip mode was dependent on other factors - e.g. the
> > nature of the event. For example the convention for personal
> anniversaries
> > may be different than that for "legal" ones. Previously I cited the
> > Gregorian example of someone born on a leap day who prefers to celebrate
> on
> > the 28th, but legally is not considered to be "of age" until the 1st.
> >
> > The bottom line is conventions for one calendar system can vary from
> locale
> > to locale and it would be very hard for us to define the basis for that.
>
> Ack.
>
> But, then, I still don't see how using possibly complicated SKIP
> controls really works here.  If I create a repeating entry, my
> calendar system tries to figure out what's what and sticks in some set
> of SKIPs.  Maybe it gets them right, and maybe it doesn't.  Whatever
> it does, those are now copied to every other calendar system that I
> give this vevent to.  If it's wrong, it's wrong everywhere.
>

It may be wrong, but for all invitees the event will happen at the same
time. The most important aspect of recurring events is that they should be
consistent: if I invite you to an event it should show up at the same time
for us even if its a wrong time. Otherwise we won't meet at all, and people
get really angry about this.

In your example, the user (creater) will see when instances happen. And if
he is not happy with the implementation - he can always choose a better
system. But at least he won't have to blame Google Calendar for getting his
event wrong when some invitees using it don't show up.


>
> If we rely on the calendar implementations to do the right thing with
> respect to the particular calendars, then one implementation's bugs
> don't spread.
>
> On the other hand, if "personal" and "legal" differ, we'd have to have
> some way to convey that this vevent is personal and that one is legal.
> Oy.  I'm not worried about exceptions (personal preferences and the
> like, though I'm not sure how a calendar implementation would do a UI
> to let a user control that)... I'm worried about having most things
> get it right most of the time, and reserving explicit SKIP rules for
> the exceptions.
>
> I really don't see a way out here.
>
> b
>