Ak47 Knife Advanced

I have a friend who got the ak 47 knife adv for 20 days instead of 14. Me and him can't figure this out is it a glitch? or is it simply a fail that will be fixed or does he get it for 20 days because we were surprised big time.
http://i45.tinypic.com/6z96js.jpg
That is an img to prove it.