But, most cookies don’t have an expiration date:  They have a best-by date – and it means something entirely different.

In the United States, food date codes are used as a measure of quality, not of food safety, and are mostly unregulated, according to the Food and Drug Administration. 

Ira Allen, FDA spokesman, said that food safety is a function of storage conditions (temperature and humidity control) more than of the product itself.  And so, it regulates retail and foodservice outlets – where consumers come into possession of food products - to enforce laws regarding handling of food, equipment, waste, temperature and store environment.  

Still, there are four commonly used food date codes that consumers encounter on a daily basis:  sell by, use by, best if used by (or before) and expires by, according to U.S. Department of Agriculture. 

Food date codes are established at the discretion of the manufacturer, with the exception of some perishable products, which must have a sell-by or use-by date, according to the FDA. Products can be consumed after the sell-by date for varying periods of time, but should not be consumed after the use-by or expires-by date. Products such as cookies or potato chips have best-by dates to indicate freshness and can be consumed after the date listed, said Regina Hildwine, senior director of science policy, labeling and standards at the Grocery Manufacturers Association in Washington, D.C. 

But food retailers routinely take products off shelves that are past the sell-by or best-by dates. Instead, retailers, including Jewel-Osco, donate millions of pounds of food that is past the sell-by date.

“Though freshness declines after the sell-by date, many products will continue to remain nutritious and edible for an extended period, and freezing items, such as meat and baked goods, can further extend their life,” said Karen May, communications manager for Jewel-Osco.

The Greater Chicago Food Depository, which receives such donations, meticulously sorts through these items based on date codes.

“If it’s supposed to sell by a certain date, we check how far we can push that out so the product is still edible,” said Meaghan Farno, public relations coordinator for the depository. “Usually things that are donated go out pretty quickly.”