Thanks for a bug report. I tried to reproduce this with the latest development version and with 3.22.6, but no luck, I can edit already existing contact, changing its Birthday or setting Anniversary day and the server doesn't claim anything.

I recall the same error when creating new contacts, but it was from a CardDAV calendar, not from Google.

Could you run evolution-addressbook-factory from a terminal with some debugging on, to see what it does in the background and what the server responses, please? The commands in the newly started terminal would be:

   $ export G_MESSAGES_DEBUG=all
   $ export LIBGDATA_DEBUG=255
   $ /usr/libexec/evolution-addressbook-factory -w

then wait for 5 seconds, thus D-Bus has enough time to register the new service, and then run evolution and try to reproduce the error. The console will contain raw communication between the server and the client, thus also the information about the contact, but I'm not interested in that information, I would rather want to know what headers had been passed to the server and what exact error the server returned, together with the used format of the birthday value.

By the way, what is your exact version of libgdata, please? It's used with the Google addressbooks.

Closing this bug report as no further information has been provided. Please feel free to reopen this bug report if you can provide the information that was asked for in a previous comment.
Thanks!