[horde] Problem kronolith

[Ruud Baart]

Thanks, I made a bug report in Bugzilla. Hope they find a solution.

My (ugly) temporary work around for the moment is to make a progresql 
cronjob that looks for null values in the kronolith_events table and 
fill these with our timezone (Europe/Paris) and adjust the modification 
time. With a sync of the calendar it should be fine for the users.


Op 2026-02-25 om 10:54 schreef Ralf Lang:
> Hi Ruud,
>
> yes, I read it that way. Now telling Thunderbird to change is beyond 
> me unfortunately. It's a wholly different beast I fear.
>
> Ruud Baart <r.j.baart at prompt.nl> schrieb am Di., 24. Feb. 2026, 15:40:
>
>     Thank you for this explanation.
>
>     Are you referring to this in the RFC 5545:
>
>     "The use of local time in a DATE-TIME or TIME value without the 
>     "TZID" property parameter is to be interpreted as floating time,
>     regardless of the existence of "VTIMEZONE" calendar components in
>     the iCalendar object."
>
>     This means: no timezone -> local time. And what local time is that
>     depends on where you are. Correct?
>
>     It also means the Thunderbird calendar cache is faulty. It should
>     not store "UTC" if timezone is empty. Correct?
>
>
>
>     Op 2026-02-24 om 15:22 schreef Ralf Lang:
>>     Hi Ruud,
>>
>>     it's a good idea to increase data quality but it also introduces
>>     some new problems.
>>     |VEVENT| components without explicit |VTIMEZONE| entries are
>>     valid in iCalendar (RFC 5545) and CalDAV, provided they follow
>>     specific formatting rules for their time values.
>>     We have to accept events, ics files, invitations etc from other
>>     software products or from legacy data imports.
>>
>>     However we can define that we internally handle them with
>>     timezone and always create/export them with timezone.
>>     Which leads to a whole other category of fun whenever one
>>     software product uses a timezone another doesn't know.
>>
>>     We will probably need to work on how exactly we achieve this
>>     timezone compatibility the right way.
>>
>>
>>     On Tue, Feb 24, 2026 at 3:13 PM Ruud Baart <r.j.baart at prompt.nl>
>>     wrote:
>>
>>         Hi,
>>
>>         approximately 30,000 appointments are stored in the Horde
>>         database,
>>         roughly half of which do not have a time zone stored. That
>>         works fine in
>>         itself, but lately it has been causing problems in Thunderbird.
>>
>>             horde6=# select count(*) from kronolith_events where
>>         event_timezone is null;
>>               count
>>             -------
>>               13677
>>             (1 row)
>>
>>             horde6=# select count(*) from kronolith_events where
>>         event_timezone is not null;
>>               count
>>             -------
>>               17499
>>             (1 row)
>>
>>         If I have analyzed it correctly, this is because
>>         Thunderbird's calendar
>>         converts the null value to UTC in its cache (sqlite
>>         databases). That is
>>         not the correct value. So registering an event works fine,
>>         but when you
>>         reopen Thunderbird, the display is incorrect.
>>
>>         I would like to see Horde make a time zone mandatory when
>>         storing
>>         events. If the time zone is missing, it should take the time
>>         zone from
>>         the preferences, and if that is not possible, it should take
>>         the system
>>         time zone. I am not sure if my wish is already achievable
>>         through the
>>         configuration of Horde.
>>