HI MichiEck
Just seeing if you have found a solution for your problem? We are having s similar issue as we are trying to searh for all members (4,000 of them) who had a birthday in a particular month so we can send them birthday cards, but it does not allow us to search who had a birthday in the month of March for example.
It seems to only search for the actual date they were born, which would be a massive task if we had to do that for every month.
Jason