Understanding How to Read Food Expiration Date Codes

To read food expiration date codes, learn the different types of dates used for expiration codes. Determine if the code is using letters for months, the Julian calendar or a month-day-year code.

In the United States there is no standard system for dating food, according to the Department of Agriculture. The only exception is infant formula, for which Federal regulations require a "Use-By" date on the product label. Understanding the various formats the date may be written in, however, allows one to read the expiration date.

Opening and Closing Dates
Opening dates are found on perishable foods such as eggs, dairy products and meats. These dates are displayed with a "Sell-By" or "Use-By" or "Best-If-Used-By" reference. The date helps the store know how long to display the product for sale, and it helps the consumer know the time limit for using the product at its best quality, according to the Food Safety and Inspection Service, which is the public health agency in the U.S. Department of Agriculture (USDA).

Closing dates are found on cans, boxed foods and other shelf-stable foods. These codes are packing numbers used by manufacturers. Packing numbers allow manufactures to track and rotate their stock as well as locate their product in the event of a recall.

Decoding Food Expiration Codes
All U.S. manufacturers label their food products with codes. These codes can appear as letters, numbers or a combination of both.

A letter signifies the month. January is "A," February is "B," March is "C," April is "D," May is "E," June is "F," July is "G," August is "H" and September is "X" because the letter "I" is usually omitted. October is "J," November is "K" and December is "L." If there is a letter, the numbers next to it indicate the day and year. The year may be at the end or beginning of the code.

The code may use the standard month (M), day (D) and year (Y) system. This system can be coded either YYMMDD or MMDDYY. Remember that the month digits can only be from 01 to 12 and that the day digits can only be between 01 and 31. The other date should be the year.

If the code does not resemble either of the previous codes, it is most likely using the Julian Calendar, which assigns a number for each day of the year from 1 to 365. The year will usually be listed with one or two numbers. In the Julian calendar, January is 001 to 031. February is 032 to 059. March is 060 to 090. April is 091 to 120. May is 121 to 151. June is 152 to 181. July is 182 to 212. August is 213 to 243. September is 244 to 273. October is 274 to 304. November is 305 to 334. December is 335 to 365.

The various codes and numbering systems cause consumer confusion, which results in consumers discarding wholesome food. The USDA estimates that 30 percent of the food supply is lost or wasted at the consumer and retail levels.

Dating Infant Formula
Federal regulations require manufacturers to include a "Use-By" date on their product label of infant formula. If the formula is consumed by the "Use-By" date, it ensures the formula contains the nutrient quantity as listed on the label. Consumers are encouraged not to buy or use baby formula after its "Use- By" date, as stated by the Food Safety and Inspection Service.