Address Book allows you to enter birthday information for each contact. Some Sony Ericsson phones show this information. If you later delete the birthday information in Address Book and sync the contact to your phone via iSync, some phones will correctly delete the birthday information. However, the birthday data may be replaced with 01/00/00.
If your phone replaces the birthday data with 01/00/00, delete the birthday information on the phone instead of Address Book.
Important: Information about products not manufactured by Apple is provided for information purposes only and does not constitute Apple's recommendation or endorsement. Please contact the vendor for additional information.