@nprofile1q... Poettering:
BTW, just to emphasize this, and explain why i think adding this to userdb is fine:
i actually believe that making sure apps cannot just read the birthday field is a good idea, but it's just one tiny piece of data among so so much more important stuff. if people run apps unsandboxed these apps get access to any file in $HOME and a tonload more stuff of the system. And that data is a lot more valuable than the birthday is. Hence, let's maybe not waste discussion around isolating apps from that single piece of information that is the birthday, while leaving everything else wide open.