Actually it is not a "is more or less a known problem" what ever instance I have investigated turned out to be was a read only calendar. Which made updates impossible.

Is your calendar with one of the major mail providers like outlook, google yahoo or GMX? I have also seen folks using network based ICS files that are read only as well, but generally there is a workaround. Mostly I ignore calendar topics because really I rarely use it. but it is quite topical with V91 as there does appear to be some bugs that have surfaced.

Hi Matt,

I'm connected to my companies google calendar (google workspace) via CalDav. The calendar is the only one and it is not read only. I can create events and some reminders are dismissable (if that's the correct word). I spent some time on this reminder issue but couldn't figure out what the problem is. I have to admit that I'm not an expert for such topics, for instance I do not understand why the calendar needs to be writable for dismissing a reminder. However, this is the reason I would like the notifications to work when reminders are disabled.

Cheers

My understanding is the dismissal is logged in the file.

Now I don't have access to a google workspace, so must extrapolate from what I can access. But V91 of Thunderbird has brought with it a "new" way to set up google calendars and is is mostly better, but it has caused some issues with google oauth for the odd few.

SO lets start at the beginning. In your account settings on google web site is the group calendar subscribed and listed? If so.

Add a new calendar to Thunderbird. tell it your user name and leave the URL part of the dialog blank and click the discover or find button.

is your calendar found?

If you have not authorization or nothing really, you might need to go to the passwords part of preferences and remove all your google passwords so it can start again (this is the trouble part I mentioned earlier) so Google can correctly authorize the access to calendars.

Hi Matt,

thanks for your reply. I can connect to the calendar and everything. I observed the following:

If person a@gmail.com sends an invitation to b@gmail.com the reminder for the event is defined by the respective setting of the calendar in google. I. e. if person a@gmail.com has defined a reminder for 10 min prior to the meeting it is saved in his calendar. The invitation (ics file) itself does not contain a reminder (ical VALARM section). If person b@gmail.com defined reminders 30 min prior to meetings the event will have the 30 min reminder and not the 10 min reminder person a@gmail.com defined when creating the event. Now if there are already events defined in the google calendar and the calendar is set up in Thunderbird the reminders are somehow recognized by Thunderbird but I guess as there is no real VALARM section in the event the reminder cannot be dismissed. For me it seems complicated and I'm not really deep in this iTIP / iMIP topic that's why I wanted to activate the per calendar notification and disable the reminders.

I found a workaround that seems to work for me, but I'm still testing. In google there is an option "Show events automatically created by Gmail in my calendar". If this is active new events for invitations included in emails are added automatically to the calendar with the reminder setting as described above. So I deactivated this feature and now the event is only added after I responded to the invitation. If I use the buttons in Thunderbird the event is added to the calendar as it is defined in the ics file of the invitation meaning without any reminder. So I now have a lot of events without any reminders but with the new per calendar notification option I get notified about upcoming events.

I hope this description is not too confusing.

Cheers