Address Book on the Mac is a great app to capture your contact info and it syncs nicely with the Contacts app in iOS. It is also a great app to store the birthdays of your friends and relatives, and you can get reminders from iCal app.
Birthdays however is not included in the default template in Address Book, thus by default you are not able to view and edit the “Birthday” field of your contacts. To add in “Birthday” field into the default template, open the Address Book preferences and select the “Template” tab:
Click on the “Add Field” drop-down below the tab icons, and select “Birthday” on the drop-down list.
Address Book contact detail will now display “Birthday” field for you to view and edit the birthdays of your contacts.
To display the birthdays on iCal, you need to enable this feature. Open up iCal preferences. Tick the “Show Birthdays calendar” checkbox.
That’s it. A new “Birthdays” calendar will appear on your calendar list which contains the birthdays from your Address Book.
The birthdays inside Address Book and iCal are synced. You can only add, remove or edit birthdays from Address Book app. When you try to edit a birthday from iCal, the app will prompt you to open Address Book app for the edit:
Any time you add, remove, or edit birthdays in Address Book app, they’ll automatically be updated in iCal.