From my experience I have found that you need twelve months now on all passports from the date of RETURN. This seems to be a standard policy worldwide, as I have just renewed my UK passport as it had 6 months left to expiry following my return into the UK in August. The passport agency stick any outstanding time onto your new passport.I.E a ten year passport renewal on a passport with 7 months left on it becomes a ten year 7 month passport