2011. He was a guest on the 9th of March and also the 7th of July but to answer your question. He was a fill-in for Dave from the 4th of April 2011 up until the 8th. On the 8th Pete Tong made an in studio appreance.
"Goodbye Great Britain" Chris Moyles final words on BBC Radio 1 (Friday 14th September 2012)
"Hello Again Great Britain" Chris Moyles first words on Radio X (Monday 21st September 2015)
Jaymo and Andy George? No, it's Andy George and Jaymo!
I remember downloading that first half-hour of the following show (from this very forum) and keeping it in my iTunes just to listen to it whenever I wanted. Favourite part is when the team break down after the "Try not to make a hash of it" bit and Dave's voice when he says " I know, it's beautiful"