Thanks folks for your responses. I chose this particular forum to place my question as I thought that this place would be followed by most of the contributors who could provide an answer for me, as I'm well out of touch with current policy.
By the way, it's not me that's retiring, but thanks for your words Chock Chucker, I've been retired absolutly yonks! The reason I asked the question is that I'm selling my house and it's a newly retiring Serviceman who is buying it, and therefore vacating his quarter somewhen. I'm trying to find out when this must be without actually asking him!
Thanks again
MTB