How do I get rid of Facebook birthdays from the Sense Calendar?

[CannedBullets]

So I woke up and found that my M8 annoyingly has my FB friends birthdays in the Sense 6 calendar. How do I get rid of them? I can't find any settings in the calendar or Facebook apps.

 

[Geezerb]

I think it's in settings_sync

Sent from my HTC One M8