Many shoppers notice unfamiliar numbers printed on egg cartons and wonder what they mean. Besides the regular date, cartons often include a three-digit code, a plant code, and other markings that can seem confusing. However, these numbers provide useful information that can help you choose fresher eggs and better understand how they were processed.

One of the most helpful markings is the **Julian date**, a three-digit number that shows the day the eggs were packed. As the article explains, **”The system starts with 001 for January 1 and continues through 365 for December 31.”** Comparing the Julian dates on different cartons can help you select eggs that were packed more recently.

Another important marking is the **plant code**, usually shown as the letter **”P”** followed by numbers. This code identifies the facility where the eggs were processed and packed. While most shoppers may never need it, the information becomes valuable if a product recall or food safety issue occurs.

Many cartons also include a **”sell by”** date, which is often misunderstood. This date is mainly intended to help stores manage inventory and does not necessarily mean the eggs are unsafe after it passes. When eggs are properly refrigerated in their original carton, they can often stay fresh beyond the printed date. Keeping eggs in their carton also helps protect the shells, reduce moisture loss, and prevent them from absorbing strong odors from other foods.

Before using eggs, you can check their freshness in simple ways. The water test is a popular method—fresh eggs usually sink, while older ones may float because air builds up inside the shell. You can also crack an egg into a separate bowl and look for a firm yolk and thick egg white. Understanding these carton labels and freshness checks makes buying and using eggs much easier, helping you make smarter choices every time you shop.