 <p>You can set a birthdate to a contact (through the Contacts app) with only a month/day. The year is then set to 1604, it's just not shown. If before you do your ABRecordSetValue(), you set the year to 1604, the birthdate will show as just "May 5" when viewing the contact in the Contacts app. It appears as though this is the way Apple specifies 'no year'. You will have to manually check the date later if you plan on showing it otherwise you will display the 1604 year.</p>