Re-Confirm email address yearly

Is there a way to have users (who are registered and confirmed already)have their email address re-confirmed every year on the same date?

You could try unconfirmed everyone manually or try using a database query on _comprofiler to set them all unconfirmed then use the Resend Confirmation button in CB > User Management. Aside from that no, there is no such feature to do this.

Yeah, that's what I expected. I guess it would be possible if there was some Auto Action trigger based on the date.

I would like to have this automated for my client, so manually is no option.

CB Auto Actions acts on a CB trigger so it can't really help in such a situation as there's no trigger to check against and it has no way of parsing through every user. Not really a job for CB Auto Actions. You need more of a custom CB plugin or extension that has an endpoint you could use in CRON so it could be scheduled to do all this automatically.

The new Auto Actions 5.1.3 adds CRON jobs support. Now I had a quick look at it, but I'm not certain.

Will this new feature enable me to set up my request form the topicstart?
And if so, how? I do have CRON support at my host.

You don't have to use CRON. You can navigate directly to the URLs within CB Auto Action > Config > Internal to trigger the actions. You need to edit your actions and add the "Internal General" and/or the "Internal Users" triggers for the URLs to fire that action. Note you need to be careful combining it with other triggers, because it won't have any variables except user object.

Will this new feature enable me to set up my request form the topicstart?

Possibly. You'd need 1 action to set them as unconfirmed. Then another action to send them a confirmation email. It maybe better to use a single Code action and use PHP method with CB API calls to do this though.