I put a cambelt on our 1996 (107,000 miles now ) 1.8 GLX Auto last
year.  The first belt change - at 54k - was by the Dealer and they
must have used a big air impact wrench because I had a devil of a
job to get the crankshaft pulley bolt undone.

I also did the water pump and roller  tensioner at the same time
last year as the cambelt - because if either seizes you are again
in big trouble, and we were over the 100k.

So my Carisma has done the 54k on each belt, and probably 5-6
years elapsing on the second belt.

Sorry cannot answer the time limit question, but I would be
thinking of a belt change if I were you.

Most modern engines do a pretty good wrecking job if the belt goes
- I think it was only older Ford and Vauxhall of the early 80's
(Cortina/Pinto engine etc) where the pistons did not smack into
the valves.

On K series Rovers it is 60k / 5 years - eg on my Son's Vi twin
cam.

CW