bureaucracy. Like food and medications, it has to have an expiry date printed on it. With spices and honey, these dates are BS. Those never spoil (though the taste will change). Medications won't necessarily turn to poison (the way food does), but it may lose potency. May. With poison, the chemical composition will also change with time, though it depends on the kind of poison and how it's made if it maintains its potency. In the end, though, the printed expiry date is a case of bureaucratic specifications.

Honestly, it is a very good question, but it is not the product or the date, but rather the result, a phrase that we must apply to all fields of life.