[horde] Problem kronolith

[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.
>
> --
>
> Cordialement,
>
> *
>
> R.J. Baart
>
> *
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