Birthdays are not part of the Google Apps Directory. There are two places TeamTools looks for birthdays. First, TeamTools looks to see if your Google Apps administrator has introduced a Custom User Field called “birthday”. This might have been done using the Directory API or using Google Apps Directory Sync to synchronize to a LDAP directory server.
If no such Custom User Field exists, then TeamTools looks for a Google+ profile which includes a birthday field. If this field exists and is shared with the organization, then it appears in TeamTools.