I'm back and confused after after looking it up in the London Gazette - my LE Comission from WO1 says that I was promoted 2Lt 5 years prior to my actual commissioning date, promoted Lt 4 years prior to my actual commissioning date and promoted Captain on my actual commissioning date. So I guess that's how it's done for LE Captains but promotion to Major is/was done by selection after 4 years seniority (Captain) and published on the beige list so goodness knows how this bloke goes straight to Field rank! But times do change.