You can find your friends' birthdays, if they're visible, on the Facebook desktop website or Facebook mobile app.

How to Find Friend Details on Facebook. Your friends' Facebook profiles likely hold more information about them than just their status updates and messages friends post to their walls. You may ...

How to See Which Friends Leave You on Facebook. Facebook does not send any alerts when someone unfriends you on Facebook for privacy reasons. However, your friends list on Facebook contains a ...