Understanding Expiration Dates

There’s no standardized system for food dating in the US, which makes understanding numbers on food packaging confusing. Approximately 40 states require dates on some perishable foods, like meat and dairy, but what do those dates or numbers actually mean?

Some are best by dates, some are production dates and some are lot numbers. But it’s important to remember that most food products are safe to consume past the date on the label, according to the USDA’s Food Safety and Inspection Service (FSIS). Read below to see what kind of dates and numbers you might find on your groceries.

Source: https://www.realsimple.com/food-recipes/shopping-storing/food/food-expiration-dates-guidelines-chart#citation-2. Accessed 10May2023)

Alison’s Pantry freezes all of our refrigerated items upon receiving them. The shelf life of items that are frozen are extended +1 year from marked date.

Types of Dates

Depending on where you live, you may see different dates on your food and each has a different purpose. Here’s a bit of clarity based on information from the Institute of Food Technologists (IFT) and FSIS.2

Best If Used By/Before: This is a quality assurance date and serves as a “suggestion” for when the taste and quality of food are at their peak. It is not a purchase or safety date.

Use By: This is the suggested date by when you should eat the food. But just because it’s a day or two past the use-by date doesn’t mean that consuming it will make you sick, although you should evaluate the quality of the food yourself after this time. It is not a safety date, except when used on infant formula.

Sell By: This is not a safety date, but rather a date for retailers that helps them determine how long an item should remain on the shelf. According to the IFT, “one-third of a product’s shelf-life remains after the sell-by date for the consumer to use at home.”

Freeze By: According to the USDA, this date indicates when a product should be frozen to maintain peak quality. It is not a purchase or safety date.

Closed or coded dates: These are packing numbers for use by the manufacturer and usually on dry goods. They can include lot codes and manufacturing locations or production dates.

(Source: “How to Read Expiration Dates” https://www.realsimple.com/food-recipes/shopping-storing/food/food-expiration-dates-guidelines-chart, Institute of Food Technologists (IFT), ScienceDaily, The Difference Between “Use-By” “Sell-By” and “Best-By” Dates. Accessed Jan. 18, 2023.)

Expiration TypeDate FormatExampleDate DetailsExplanation
Best if Used By/Before
or BB (Best By Date)
Letter-DD-YYE1522 = May15 2022Read the letters as though they were assigned to months. For example letter A is “01” or January, letter B is “02” or February.Date indicates when a product will be of best flavor or quality. It is not a purchase or safety date
Sell ByMMDDYY051522 = May 15 2022Date tells the store how long to display the product for sale for inventory management. It is not a safety date
Use ByYYYY-MM-DD2022-05-15 = May 15 2022Date is the last date recommended for the use of the product while at peak quality. It is not a safety date except for when used on infant formula as described below
Freeze ByMM/DD/YYYY05/15/2022 = May 15 2022Freeze by Dates will usually be labeled with a “Freeze by” marking. We freeze all of our refrigerated and frozen items. The Shelf life of items that are frozen are extended +1 year from marked Date.Date indicates when a product should be frozen to maintain peak quality. It is not a purchase or safety date
Expiration DateMM/DD/YYYY05/15/2022 = May 15 2022The date after which a product should not be sold because of an unexpected decline in quality or effectiveness
Manufacturing DateMM/YYYY or DD/MM/YY05/2022 or 15/05/22 = May 15 2022Manufacturing Dates usually have a time stamp next to the date.Date when the product was manufactured
Production DateYY/WW22/19= Week 19 (May 9th to May 15th) of 2022The first two digits indicate the year while the 3rd and 4th digits indicate the week of manufacture. Production Dates may have a time stamp next to the date.Date when the product was assembled
Julian DateYY-DDD22-133 or 22133 = May 15 2022The first two digits are the last numbers of the year and the three digits after the hyphen are the day of that year.The Julian date usually represents the date the product was manufactured or packaged
Lot Code or
Batch Code
———-Lot Codes can be any combination of numbers and letters that follow the manufacturers format for tracking product batch’s and manufacturing dates.Lot Codes (Batch Code) must be identified with the Manufacturer.

Other resources:

www.fsis.USDA.gov: Food Product Dating

www.realsimple.com: It’s Usually Safe to Eat Food Past the Expiration Date—Here’s How to Know When It’s Ok

www.heart.org: Understanding Expiration Dates: How do I know when my food’s gone bad?