Re: [calsify] Shepherd Review of draft-ietf-calext-caldav-attachments

[Paul B Hill <[e-mail]>]

Hi,

If I recall correctly, while letting the server simply match the RECURRENCE-ID is a nice side effect, there are edge cases where the requirement is essential in order to guarantee the correct behavior. Recurring meetings happen over a span of time AND timezone definitions change over time. The timezone definitions include not only the offset at a particular time of year, but also the geographic region to which the rule applies. When the specification was being developed there was one region that had overlapping timezones and the choice of which timezone was applied implied a political affiliation (in a war zone.) Performing a translation on each server to which the iCalendar instance may be forwarded prior to storage could lead to confusion.  Of course, the organizer may reside in an area where there is timezone instability over the duration of the recurrence, but presumably, the organizer would be in the best position to know that an issue updates as needed. 

Paul

-----Original Message-----
From: calsify [mailto:[e-mail]] On Behalf Of Ken Murchison
Sent: Thursday, April 13, 2017 2:26 PM
To: Philipp Kewisch <[e-mail]>; Calsify <[e-mail]>
Cc: [e-mail]
Subject: Re: [calsify] Shepherd Review of draft-ietf-calext-caldav-attachments



On 04/13/2017 06:05 AM, Philipp Kewisch wrote:
> Hello All,
>
> I've gotten around to finishing my review on this document. Aside from 
> a minor typo, I have two simple questions, just to clarify out of 
> personal
> interest:
>
>>     Specific instance  A specific iCalendar instance is targeted by using
>>        its "RECURRENCE-ID" value as the item value.  That value MUST
>>        correspond to the RECURRENCE-ID value as stored in the calendar
>>        object resource (i.e. without any conversion to UTC).  If multiple
>>        items of this form are used, they MUST be unique values.
> Can you clarify why you chose to not allow specifying this value in 
> any form, so that the server does timezone translation if needed?

I don't recall the exact reason, but presumably its so that the server can simply match the RECURRENCE-ID by value without having to do any translation.  Perhaps Cyrus and/or Arnaud remember the exact reasoning.