Re: [Tzdist] Fwd: [tzdist] #32 (service): managing historical data

Doug Royer <douglasroyer@gmail.com> Thu, 11 December 2014 17:53 UTC

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Date: Thu, 11 Dec 2014 10:52:55 -0700
From: Doug Royer <douglasroyer@gmail.com>
Organization: http://SoftwareAndServices.NET
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Subject: Re: [Tzdist] Fwd: [tzdist] #32 (service): managing historical data
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On 12/11/2014 10:00 AM, Cyrus Daboo wrote:
> Hi Doug,
>
> --On December 11, 2014 at 9:47:12 AM -0700 Doug Royer 
> <douglasroyer@gmail.com> wrote:
>
>>> Which is EXACTLY the problem that tzdist SHOULD be addressing. Just
>>> perpetuating the current mess is simply not acceptable, and any draft
>>> which does that should not be allowed forward.
>>
>> Its not a problem unless you ignore what the organizer sends. Its more
>> relevant that
>> everyone agree with the organizer, than with some other source.
>
> Except that many clients DO ignore what the organizer sends - they 
> just assume that if the TZID in the iCalendar data matches one they 
> have locally, then the local definition is used in place of any sent 
> in a VTIMEZONE. i.e., they throw away the organizer's copy of the 
> VTIMEZONE in favor of there own.

Their code will have to change ether way or they will be just as broken.

They have to add code to fetch the correct organizers TZ data and 
recompute it themselves and hope they get it from a compatible source . 
Or they have to add/update code to use the organizers included data.

If the organizer is responsible for redistribution, then irrelevant or 
out of event time changes do not need to be fetched or recalculated by 
every CUA for every event every time the CUA starts. The organizer 
simply iTIP dispatches on relevant changes only.

> One of the goals for tzdist is to ensure that when clients do that, 
> they have a reasonable chance that their local time zone data matches 
> what the organizer had (i.e., organizer and attendees are in sync wrt 
> the VTIMEZONE data).
>

Yes, and and that is great separate point!!

When translating from organizer TZ to the local-TZ, the CUA can 
determine if it needs to get the latest local-TZ information for 
accurate results.

-- 

Doug Royer - (http://K7DMR.us / http://DougRoyer.US)
DouglasRoyer@gmail.com
714-989-6135