The friend_request stream contains 2 fields - uid_from and uid_to. There is no date when the request was made.
Is there any other table containing this information?
Thanks!
Got a word on Facebook forums - it's impossible
You can track it yourself, on an ongoing basis, but by subscribing to friends' events. The subscription API is subject to real-time updates. Not sure what you are trying to do. http://developers.facebook.com/docs/api/realtime
If you look at http://facebook.com/me?and=you for new friends, it shows that their date has been added. This data is publicly available and needs to be stored somewhere openly.