Allright...thinking around the corner, here comes a solution:

I use Thunderbird. Installed CardBook, which has a function to extract BDays and others events, and writes it to Lighning Calendar of Thunderbird. You can choose which Cal. gets the snyc.

And bc. this Lightning Cal. I chose is the Baikal one, it get's updated in Baikal Server Cal. and hence in all other subscribed Calendars. 😎

Happy new week folks & tnx again for your engagement to help me. 🖖 :underheart: