Understanding How to Read Food Expiration Date Codes


No one wants to purchase food that is out of date. Although examining the food for signs of spoilage is one way to check its quality, understanding how to read food expiration date codes ensures that you can always determine where food is at in its lifespan. With open dating expiration dates, you only have to read the date to know when the food expires. However, with closed coded expiration dates, you must understand the procedures typically followed by food manufacturers.

The Open Dating Expiration Code

The open date dating expiration code is commonly found on items with a relatively short shelf life like eggs, milk, and fresh meat. However, you may also find it on items with longer shelf lives, including so-called “nonperishable” items. 

An open dating expiration code reads exactly as it’s written. An open dating expiration code is written as and reads as a calendar date. For example, if a gallon of milk has a best by date of 12/30/19, you should read this as December 30, 2019. 

The Closed Coded Expiration Code

A closed coded expiration code is a little trickier to read as it consists of letters and numbers that identify when the manufacturer produced the item. Closed coded expiration codes are used by the manufacturer to assist with inventory tracking, and procedures vary with different companies.

In some closed coded expiration dates, letters are used to signify months. For example, A corresponds to January, B indicates February, C means March, and so on. After the letter, numbers are typically used to indicate the date and the year. If the code reads D0519, the date is April 5, 2019. Some closed coded systems use the entire calendar when denoting the day; this means that they use a number for each day of the year, up to 365, so C6019 would read March 1, 2019.

Some companies use numbers to label the first nine months of the year and then use letters for the last three months of the year. If the company follows this model, the last three months are labeled using the letter that the month begins with (O for October, N for November, and D for December). A date that reads O3119 indicates an expiration date of October 31, 2019.

It’s also possible for the company to use all numerals for the date. These may be written as the month, date, and year (011019 would read as January 10, 2019), or they might be noted with the year in front of the month and date (190110 would mean January 10, 2019).

Understanding Variation in Language Used for Expiration Date Codes

Many open dating expiration codes have verbiage in front of the given date. Some of the most commonly used phrases include:

  • Best if used by or before: Indicates that the food has optimal quality and flavor prior to this date. It doesn’t mean that the food is unsafe to eat after this date.
  • Sell-by: The date by which the retailer should offer the product for sale. Food is still safe to consume after this date.
  • Use-by: Provides the last date that the product has peak quality
  • Freeze-by: The data you should freeze food by to preserve optimal quality

One exception to these guidelines is infant formula. It’s labeled with a use-by date. However, you should not use the formula after this date. The nutrients in the formula begin to degrade after this point and may not offer all the nutrients that your baby needs.

Guidelines for Using Food After the Expiration Date

Most foods are safe to consume after their expiration date, although the flavor and quality may not be optimal. Use your senses to determine if food has expired. If the food smells weird, has a bad flavor, or has an odd texture, it’s likely the food has spoiled and should no longer be eaten. 

Tips for Extended the Lifespan of Your Food

There are a few things you can do to extend the lifespan of your food. Store perishable foods in the refrigerator whenever possible. Make sure that the temperature is set to 40 degrees or less. You can prolong the lifespan of the food even more by freezing it. 

Avoid storing perishable foods in direct sunlight or in areas where the temperature fluctuates. For example, perishable foods stored on the shelf in your refrigerator tend to last longer than those stored in the door of the fridge.