Ever wonder what the dates stamped on food packages mean? Dates stamped on foods are quality indicators not safety indicators, in most cases, and there’s no uniform system, says Christine Bruhn, PhD, Cooperative Extension Director at the University of California, Davis. Still, you should know how the “dating game” works to ensure you’re eating safe food.

Who has the most reason to pay attention to the dates? Those taking immunosuppressant drugs or using non-steroidal anti-inflammatory drugs (NSAIDs) along with a proton pump inhibitor like omeprazole (Prilosec) are at higher risk for food-borne illnesses, says Gregory Albers, MD, University of California, Irvine. People older than 50, who typically experience changes in stomach acidity and become less adept in destroying bad bacteria are at greater risk, as are children.          

“The dates provide guidelines, but use common sense,” says Bruhn. “Check for mold, off-color and off-odors, and make sure you store your foods in a properly cooled refrigerator.” To help make sense of food dates, follow these tips:

Sell by” is the last date the company wants the food to be sold. These instruct grocery or restaurant staff when to pull products off the shelves.
Common on: Milk, cheeses
Tip: Most products, including milk, are safe seven to 10 days after the date if stored properly at 40ºF or below, with minimal time out of the refrigerator. Deli meats are safe to eat three to five days after this date.

“Best by” or “best before” are freshness or quality assurance dates that manufacturers suggest for peak quality. Foods may lose some flavor or texture after the date, but in most cases are safe to consume.
Common on: Eggs and frozen, dried and canned foods.
Tip: Eggs are typically good for three to five weeks beyond this date, assuming they’re stored in a cold section of the refrigerator in their carton.

“Packed” or “processed” are package dates included to help you decide freshness.
Common on: Meats and seafood
Tip: Buy foods that have the most recent packaged date stamped on its packaging.