Are hard cheeses safe to eat past expiration date?

Possibly, but it is not worth the risk. Cheese tends to develop mold after it reaches the expiration date, and the mold is not always easily visible. The manufacturers put the expiration dates on foods for the safety of consumers, so please, don't ever eat any food past the expiration date - it simply is not worth the risk. Food borne illnesses kill many people in the US every year.