Many food packages have a date on them, along with the words “sell by,” “best if used by” or “use by.” This information can be confusing. Does it mean that the food is unsafe to eat if the date has passed? Do you need to throw it away? Most often, the answer to those questions is “No.” “Sell by,” “best by,” and “use by” dates are used to ensure good food quality. They are not safety dates.