How to get the CNContact from a birthday EKEvent

From iOS 9, the EKEvent property birthdayPersonID is deprecated.

How can I get the CNContact associated with a birthday event?

Solution

If you try using birthdayPersonID, it will produce a warning that says:

warning: 'birthdayPersonID' is deprecated: first deprecated in iOS 9.0 - Use birthdayContactIdentifier instead

So, use birthdayContactIdentifier.