When to replace timing belt on a 1990 Toyota Camry?

Answer 1

Manual says every 60,000 miles or 24 months when operated under "severe conditions" (lots of short trips, idling, dusty region, regularly below freezing, etc...).

I would say in normal circumstances skip the 2 years schedule and go with the 60,000 mile one (you could probably stretch that out even longer since the Camry is a non-interference engine, no damage if the belt breaks, the engine just stops running).

Also consider getting the water pump replaced at the same time since it will be accessible during the belt change and not add much to the repair cost. Doing them separately will double the rather extensive labor and both items have similar lifespans.