Show birthdays in Calendar

If you use the OS X Calendar app, you can add birthdays in Contacts, and then view a Birthdays calendar in Calendar. When you add or remove birthdays in Contacts, the Birthdays calendar is updated automatically. For more information, see Show holiday or birthday calendars in Calendar

Open Contacts for me

Select a contact, then click Edit.
Enter the contact’s birthday in the Birthday field.
If you don’t see a Birthday field, click the Add button , then choose Birthday.
To add a lunar birthday, click the Add button , choose More Fields, then choose Lunar Birthday. You can change the type of lunar calendar by clicking the arrows to the left of the Birthday field.
Open Calendar, then choose Calendar > Preferences.
Open Calendar for me
In the General pane, select “Show Birthdays calendar.”

If a Facebook contact’s birthday is listed on Facebook, the birthday is automatically added to the contact’s card in Contacts.