Facebook birthdays showing up in Notification Center in iOS 6

The Problem

• Facebook friends' birthdays show up in Notification Center, occupying space and making it look confusing.
• If you press the notification by accident, it re-enables the Facebook birthdays calendar, after you've hidden it.

Attempted Solutions

• Hiding Facebook birthdays calendar in Calendar app - NO
• In Settings > Facebook, disable Contacts and Calendar. Re-enable Contacts. Seems to work, but WARNING: WILL RESET FACEBOOK CONTACTS ON YOUR PHONE, BREAKING ALL LINKS BETWEEN CONTACTS. Also, in this case, you can't use your FB calendar. Update: NO, birthdays will reappear a few days later.

Further Reading

http://forums.macrumors.com/showthread.php?t=1389620