The age of reserve gasoline is only one part of the decision. Separate fuel in an approved container from fuel in an engine, then follow the exact manual and local fire rules.
Generator Safety guides
Practical household guidance about generator safety.
Build a maintenance reminder from the generator's own schedule, using both elapsed time and operating hours instead of applying one interval to every model.
Separate a no-start from no output or an automatic shutdown, record safe observations, and find the exact model manual before requesting service.