Recurring events with timezone

Tobias König tobias.koenig at
Thu Oct 21 15:52:12 CEST 2010

On Wednesday 20 October 2010 10:33:41 Joon Radley wrote:
> Hi Andrew,

> UTC is the constant. You calculate your local time by adjusting UTC to your
> local time zone. If at any point your software assumes that UTC is not the
> constant you need to revisit it.
> Time zone and daylight savings time is a locale issue.
I guess to cover the case Hendrik mentioned, the UTC -> local time conversion 
needs to check when the first occurence of the recurring event happened.
Depending on the date it can find out whether it has been created during 
summer or winter time and therefor adapt the conversion of the current 
occurence from UTC -> local.

If it has been created during winter time and the current occurence is winter 
time as well, then the normal offset is added to UTC. If it has been created 
during summer time but the current occurence is winter time, then the hours to 
add to UTC must be adapted properly.

However this is something for the local conversion, nothing that needs saving 
timezones inside the format.

Tobias Koenig | tobias.koenig at
KDAB (Deutschland) GmbH&Co KG, a KDAB Group company
Tel. Germany +49-30-521325470, Sweden (HQ) +46-563-540090
KDAB - Qt Experts - Platform-independent software solutions
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