You’ve probably noticed it countless times without giving it a second thought: a small three-digit number printed on the side of an egg carton. It seems trivial—maybe an internal code, a packaging reference, or just clutter on the carton you can safely ignore.
But dismissing it can backfire.
That little number is actually one of the most important indicators of food safety in your refrigerator. It tells you the true age of your eggs—not how long the store wants them to stay on the shelf. Ignoring it is one of the main reasons people end up with upset stomachs, food poisoning, or ruined meals.
Knowing what this number represents—and how to use it—can drastically reduce your risk of egg-related illness.
The number is called the Julian date. It indicates the exact day of the year the eggs were packed, not when they expire or when you bought them. The system counts from 001 to 365, corresponding to January 1 through December 31.
For example:
001 means the eggs were packed on January 1.
032 corresponds to February 1.
120 means April 30, the 120th day of the year.
Once you understand it, there’s no guesswork.
It’s also important to realize what this number isn’t. It’s not an expiration date. It’s not a sell-by or best-by marker. It’s simply a timestamp—and it’s often far more reliable than any bold label printed on the carton.
The prominently printed sell-by, use-by, or best-before dates mostly exist for inventory purposes: they help stores rotate stock and reduce waste. They aren’t strict indicators of safety. Eggs can often remain good well beyond those dates if stored correctly.
Guidelines suggest that raw eggs in their shells can remain safe for three to five weeks after the pack date, as long as they’re refrigerated at or below 40°F (4°C). That means eggs are often fine even after the sell-by date—if they’ve been handled properly.
Temperature matters. Eggs spoil much faster at room temperature. Leaving them out—even for a few hours at a time—reduces shelf life and increases bacterial risk. Once chilled, eggs should stay chilled.
Many people are surprised to learn that eggs don’t always show clear signs when they’ve gone bad. They may look normal, smell fine, and cook perfectly—but can still make you sick.
The most common culprit is Salmonella, a bacterium that causes nausea, vomiting, abdominal cramps, fever, and diarrhea. Unlike spoilage bacteria, Salmonella doesn’t alter the egg’s appearance, smell, or taste. Cooking thoroughly is the only reliable way to kill it.
Salmonella can exist inside the egg even before the shell forms. Washing eggs only reduces surface bacteria—it cannot remove pathogens inside. Undercooked dishes like quiches, custards, sauces, and baked goods may not reach the 160°F (71°C) internal temperature required to kill bacteria.
Older eggs, improperly stored eggs, or eggs from contaminated batches increase risk even further. Often, when people fall ill from home-cooked meals, eggs are the hidden factor.
Using the Julian date is simple. Locate the number, usually on the short side of the carton near the USDA grade or plant code. Convert it to a calendar date, then count three to five weeks from that day—that’s your real safety window. If you’re near the end of that range, cook thoroughly or discard, especially for dishes that aren’t fully cooked.
When in doubt, throw them out. Eggs are inexpensive; food poisoning is not.
Other carton markings provide context but not safety guarantees. The grade—AA, A, or B—indicates quality, not safety. AA eggs have firmer whites and rounder yolks. B eggs are typically for processing. All grades meet safety standards at the time of packing.
Labels like organic, cage-free, or pasture-raised describe how hens are kept, not whether the eggs are free from pathogens. Organic eggs come from hens fed organic feed and without antibiotics. Cage-free hens aren’t confined to cages but may still live indoors. Pasture-raised hens have outdoor access and may produce slightly different nutritional profiles.
None of these labels remove Salmonella risk. Proper handling and cooking remain essential.
The plant code—usually a “P” followed by numbers—identifies where the eggs were packed. In a recall, this code helps trace the source.
Preventing egg-related illness comes down to habits:
Refrigerate eggs promptly in their original carton.
Avoid cracked shells.
Wash hands and surfaces after handling raw eggs.
Use a thermometer for dishes where internal temperature matters.
Pasteurized eggs offer extra protection for recipes with undercooked or raw eggs, such as sauces, desserts, and drinks. They’ve been heat-treated to kill bacteria without cooking.
That small three-digit number isn’t decoration or bureaucracy. It’s a hidden warning system built into your groceries. Ignoring it may not always cause harm, but when it does, it can be severe.
Freshness is about more than flavor—it’s about safety, timing, and attention. Reading that little stamp takes seconds; recovering from foodborne illness can take days.
Understanding your food is one of the simplest ways to protect yourself and those you cook for. That small Julian date on the carton is there for a reason.