Hi Sandra,
The Events module uses the timezones available through the core DNN Framewoork, so you can add them through the languages dialogues. However, DNN does not support DST, so there is no way to indicate whether the timezone is using DST or not. This is expected to come in future releases of DNN when supported on .Net 3.5.
The Events module does not support DST in any case, all events are shown with times as entered when adding new events, with no adjustment for DST. When sub-calendars are used and the timezone is then used to adjust event time display, (where one module instance is set to a different timezone to another), the only adjustment made is the base timezone adjustment, with no allowance for DST.
The only time when any attempt is made to allow for DST is in the sending of notifications, but even then in reality it is a best guess, where it adjusts for the DST of the timezone of the server it is running on.
No, this isn't perfect, but it is the best that can be done using the data and tools currently available. This status is the result of much discussion amongst the current (and previous) project team, and will not significantly improve until the DNN framework provides the neccesary support.
There is a mechanism for changing the timezones of all the events in the database, which should allow you as the admin to manipulate the data to deal with DST. However I've never used the capability, so can't advise on how it really works.
If this doesn't all make sense, ask more questions, and I'll try and explain when I haven't had a couple of drinks
. Also I'm UK based, and currently in San Francisco, so it feels like it is 5.15 in the morning at the moment....
Cheers
Roger