Egg cartons can be surprisingly confusing, especially when you see several dates and numbers printed on the package. One of the most useful markings is the three-digit code found on many cartons in the United States. This is generally a pack date rather than an expiration date. The number represents the day of the year, with 001 meaning January 1 and 365 meaning December 31. For example, 032 represents February 1, while 198 represents July 17 in a non-leap year.

You may also notice a code beginning with the letter “P,” which identifies the processing or grading facility. Other labels, such as “Sell By” and “Best By,” serve different purposes and are not necessarily safety dates. A sell-by date mainly helps stores manage inventory, while best-by dates are generally connected to quality. Understanding these markings can help you compare cartons and use older eggs first, but the codes alone cannot tell you whether an egg is safe to eat.

Proper storage remains much more important. USDA guidance says raw shell eggs generally keep for about three to five weeks when refrigerated at 40°F (4°C) or below. Keeping them in their original carton on an interior refrigerator shelf can help maintain quality. It is also important to remember that freshness and safety are not the same thing. The popular water-float test can indicate age because older eggs develop larger air cells, but it cannot prove that an egg is safe from harmful bacteria.

For safer handling, avoid using cracked or heavily contaminated eggs, wash your hands and surfaces after handling raw eggs, and prevent cross-contamination with other foods. When cooking eggs, FDA guidance recommends cooking them until the whites and yolks are firm. Cooked egg dishes generally keep for three to four days in the refrigerator, while hard-cooked eggs can last about one week. The simple takeaway: carton codes provide useful information, but proper refrigeration, careful handling, and thorough cooking matter far more when it comes to food safety.