Testing a mint condition Ihagee Exa (made in Dresden in 1960's) I bought on eBay (a late night impulse purchase!) with an ancient Kodak Gold 200 film donated by my 90 year old father in law...
I was very surprised that this film worked fine after all that time. I don't know the exact age of the film I am guessing 20 years. I might take more interest in the time expired film you see on eBay all the time.