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Re: [Task Scheduler] Can we really remove TimezoneDirective argument?

From: Mounir Lamouri <mounir@lamouri.fr>
Date: Tue, 03 Dec 2013 03:03:11 +1100
Message-Id: <1386000191.9717.54500725.29241143@webmail.messagingengine.com>
To: Christophe Dumez <ch.dumez@sta.samsung.com>, Gene Lian <clian@mozilla.com>
Cc: public-sysapps@w3.org, Marcos Caceres <mcaceres@mozilla.com>
On Tue, Dec 3, 2013, at 1:20, Christophe Dumez wrote:
> Hi,
> 
> Please note that timezone change is not the only thing we need to
> account for.
> We also need to account for daylight savings. To do so, you really need
> to associate each event/task with a specific timezone (which may or may
> not be the same as you are in, for e.g. you receive a calendar invite
> from someone in another timezone). If you don't store this information
> (e.g. if you convert the event/task's  time to UTC or to your system's
> timezone), then you will have no way to account for daylight savings as
> those are specific to each timezone / country.
> 
> This kind of use case is especially important for calendar applications.

Indeed. However, it is not clear to me how using TimezoneDirective would
help.

As far as I understand it, when a country has daylight saving TZ, it
technically has two timezones and swtich from one to another during the
year. France, for example, will use CET (UTC+1) and CEST (UTC+2). I
guess that there are two approaches that we can take here: whether we
give knowledge of the daylight saving information to the application or
the API could ask for a timezone in a format like "Europe/Paris" in
which case the system could take care of the TZ changes. I do not know
enough about timezones to have an opinion on this, though.

-- Mounir
Received on Monday, 2 December 2013 16:03:48 UTC

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