If you have a friend whose birthday is in December, as in the last month of the year, or maybe your own birthday anniversary is coming up next month, you’ll notice that if you fire up your People app on Android 4.2 you will not be able to add any day in December to a contact since the month itself is missing.
The issue seems to be present on the Galaxy Nexus, Nexus 4, Nexus 7, or pretty much any device running Android 4.2. Looking through the comments on Google it seems to be “a problem with the API (particularly android.widget.NumberPicker) rather than the DatePicker widget being used in the contacts app”. Until Google pushes out Android 4.2.1 or a specific refresh to fix this issue you’ll have to deal with it if one of your Contacts is born in December, regardless of the language and localization settings you use on your system.
Thanks everyone for sending this in!