What do food date codes really mean?

By: Cmdr. John Brooks and Lt. Cmdr. Richard Langton, 
Captain James A. Lovell Federal Health Care Center


We’ve all seen the “best by,” “use by,” “enjoy by” and “sell by” on food labels, but what do they really mean?

Dates stamped on a food product’s package are to help the store determine how long to display the product for sale and help the consumer know when the product is at its best quality.  It is not a safety date.  After the date passes, while it may not be of best quality, the product should still be safe if handled and stored properly.

The main thing to understand is that food-borne illness comes from contamination, not spoilage.  A pathogen has to be on your food to begin with in order for you to get sick, and it has to grow to levels that will make you sick.  Handling and preparing your food safely is more important than its age.  Except for infant formula, product dating is not generally required by Federal regulations.

The National Sanitation Foundation describes the types of dates as:

–          “Best-used-by” dates are not a safety date but rather a reference on how long an unopened food product will remain at peak quality and freshness.  Food is generally still safe to consume after this date has passed, assuming it was properly stored from the date of purchase. (51% of consumers throw food away at this date.)

–          “Sell-by” dates are intended to help manufacturers and stores determine how long a product should be available for sale. Consumers should not purchase foods after the sell by date has passed.

–          “Expiration” and “use-by” dates are safety dates.  If you can’t use a food item before this date, you should either freeze it or throw it away. Consumers should not purchase any foods past these dates.

–          “Closed or coded dates” are packing numbers for use by the manufacturer.

Storage Times

Since product dates are not a guide for safe use of a product, how long can the consumer store the food and still use it at top quality? Follow these tips:

–          Purchase the product before the date expires.

–          If perishable, take the food home immediately after purchase and refrigerate it promptly.  Freeze it if you can’t use it within times recommended on chart.

–          Once a perishable product is frozen, it doesn’t matter if the date expires because foods kept frozen continuously are safe indefinitely.

–          Follow handling recommendations on product.

–          Consult one of the following storage charts.

Some additional information on food date codes can be found at:



In depth time storage tables can be found at: