The U.S. does not have a uniform system of coding expiration dates on food products as of 2010, according to the U.S. Department of Agriculture. The federal government only requires expiration dates on baby foods and infant formula. Other dating on food products is voluntary. Open dating uses calendar dates and closed, or coded, dating is a process used by manufacturers to help with managing inventory. Closed coding is used on products with longer shelf lives, such as canned and boxed foods. The USDA notes that while closed codes could refer to manufacturing date, the codes are not intended for consumer use and no single translation source exists.
Locate the code on the product packaging. The codes, which might resemble a number like "2061" or "0195," are usually stamped on the top or bottom of a can, according to Mealtime.org, a service of the Canned Food Alliance. Look for codes on boxed foods in the same places. Manufacturers vary in listing the year or month first and some add numbers to the code that are not related to the date.
Check the code to see if numbers are used to represent months. If the code uses numbers, the numbers 1 through 9 represent the months of January to September. The letter O represents October, N represents November and D represents December. Some manufacturers use a number to represent the year, such as 8 for 1998 and 2 for 2002. Using these coding examples, 2061 translates to 2 for the month of February, 06 for the sixth day of the month and 1 for the year 2001, or Feb. 6, 2001.
Look at the code to determine if the manufacturer uses letters to represent months. If the code uses letters, the letter A represents January and each subsequent letter represents the next month, ending with L for December.
Examine the number to determine if the manufacturer uses a Julian date, which is a number that states the number of days since the first day of the current year. If a manufacturer uses a Julian date, the code 0195 will translate to the number 0 for the year 2000 and 195 for the Julian date, since July 14 is the 195th day of the year.
Contact manufacturers for specific coding information or access online information at the manufacturer’s website. Mealtime.org provides links on its website to manufacturer sites.