Army and Navy available 24/7. RAF available Mon to Fri, 0900 to 1630, subject to suitable hotel accommodation being available.
This was true once when the RAF was FJ dominated but in the transport world we've always been 24/7........the hotac part is mostly correct though.
As I never met a FAA pilot who liked being on board ship, in fact they would do almost anything to avoid that eventuality, I never could quite understand why they joined the RN in the first place. I also personally know quite a few pilots who transferred to the RAF from the RN, AAC & RM but none who have gone the other way (the odd Harrier mate who went to fly SHARs after the Falklands war excepted) which must mean something.