Entering birthdays in the OS X Contacts applicationEdit
Once you've enabled display of the birthday field, you'll find that entered birthdays will only stick if you enter them in the format, "August 10, 1974" (without the quotes, obviously).
Once you've enabled display of the birthday field, you'll find that entered birthdays will only stick if you enter them in the format, "August 10, 1974" (without the quotes, obviously).