Take the cover off and have a look at the belt. If it's all soft, supple and rubbery then it's in good nick and no point to change it. If it's hard, dirty/oily or looks cracked (inside the corners of the teeth) then change it.
The other thing... it's quite often been the tensioners failing that have killed engines rather than a belt failure itself... so check the tensioner too. If yours looks brand new, then I'd leave it in there.
I change my own belts and my opinion (probably heresy
) is that 36k is too early. The last belt and tensioner I took off were barely distinguisable from the new ones so personally I'm going to 48k next time...
I've also never seen any age-related problems. If the belt and tensioner looks good, then they probably are good. I'd say you can probably go for another 12 months.... get it to the 96,000 mile service and do it then. It'll be just 34,000 miles so should easily be feasible.... It's just an expensive gamble if it all goes **** up.
When you change your belt always change the tensioner.
At 96k I'd change the water pump too. Mine was fine at that mileage... but your next chance to change it will be at 132,000 miles otherwise, which might be too far. I change water pump every second cambelt.. but that's really too soon. You could go for 1 pump in every 3 cam-belts, I reckon.