Recurring events with timezone

[Joon Radley]

Hi,

> For example, could you please tell me exactly when, in UTC, each of the
> twelve instances next year will occur for a monthly meeting which was
> initially scheduled for the 9:00am on the 1st of the January this year
> in a timezone which (at that time) was aligned with UTC.

Does your locale functionality of your OS not provide this? If you have it in one time zone in the object and you have to calculate the dates for another user in a different time zone you still have to convert the original time: original local time -> UTC -> new local time. So in the new locale the original time zone is of no value except for calculating UTC.

> Certainly it would be possible to store some limited set of recurring
> instances on creation of the event, though that is obviously a lossy
> operation. Especially for events which are set to recur forever.

This assumes that everyone is in the same time zone. Each user only wants to see his appointments in his time zone. Else you will have to extend the format to include the time zone of each attendee as well as the time zones for their travel plans.

Converting from UTC to your locale solves this problem without trying to figure out everyones time zone. Locale is a function of the OS and not the format.

> Other calendaring software (optionally) records timezones per event for
> this and other reasons (I don't always want an event localised to my
> current timezone: sometimes I want it to be localised to the timezone I
> will be in when it will happen), so sure if Kolab clients generally are
> broken that's only a kolab problem.

This is a client issue. Why do other clients care about the time zone you wanted to see the appointment from? They are interested in the time zone they will have the appointment.

> This project that Hendrik is talking about is one that involves Kolab
> *interoperating* with client software which is not broken in that way,
> specifically Evolution.


Well again this is a client issue. Assuming all other clients except yours is broken alway points to a incorrect perspective. The KolabXML format is locale independent. The clients can show the data in the locale they want.

Best Regards

Joon Radley

Cell: +27 (0)83 368 8557
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E-mail: support at toltec.co.za
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On 19 Oct 2010, at 8:11 AM, Andrew McMillan wrote:

> On Tue, 2010-10-19 at 05:54 +0200, Joon Radley wrote:
>> Hi Hendrik,
>> 
>> There is no reason for this time zone information to be added.
>> 
>> The format is universal and the client should adjust UTC to fit the
>> users locale.
>> 
>> All other Kolab clients have been able to successfully implement the
>> UTC concept.
> 
> Hi Joon,
> 
> Did you read the previous messages in this thread?
> 
> Storing time without timezone *fails* for repeating events which are
> intended to be localised to a particular timezone for calculation of
> future instances.
> 
> For example, could you please tell me exactly when, in UTC, each of the
> twelve instances next year will occur for a monthly meeting which was
> initially scheduled for the 9:00am on the 1st of the January this year
> in a timezone which (at that time) was aligned with UTC.
> 
> Certainly it would be possible to store some limited set of recurring
> instances on creation of the event, though that is obviously a lossy
> operation. Especially for events which are set to recur forever.
> 
> Other calendaring software (optionally) records timezones per event for
> this and other reasons (I don't always want an event localised to my
> current timezone: sometimes I want it to be localised to the timezone I
> will be in when it will happen), so sure if Kolab clients generally are
> broken that's only a kolab problem.
> 
> This project that Hendrik is talking about is one that involves Kolab
> *interoperating* with client software which is not broken in that way,
> specifically Evolution.
> 
> Regards,
> 					Andrew McMillan.
> 
> -- 
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