Let users fill in there birthday.
Thanks to Omar Reygaert.
At the moment I have no idea, it's created since version 3.3.2, but I think this will still work on older versions.
This plugin should work with PHP 4.4 through last versions of php is always the best.
Since 0.1.3 there is a change in the way the plugin saves the ical-file. If you encounter problems of duplicate events, run the "rebuild birthdays" on the overview page on "Birthday users". This will cleanup the old usage and recreate it in the new way.
For some reason there went 2 breakspaces in the core plugin file. You can edit the file wp-birthday-users.php at the end by remove the breakspaces. Or you could upgrade to the last version. I'm sorry for this.