If it is a metal chain, then it should be changed at 90K to 100K.

But if it is a rubber belt.... 60K to 70K.

That is what my knowledge tells me, I am sure you already know this, but just in case you don't...

If a timing belt/chain were to break, the valves hit the cylinder heads causing servere damage.

Please make sure that you change it, but only by a competent mechanic or yourself if you trust that person in the mirror.