The useful answer: Many food dates describe quality, not an automatic safety deadline. Infant formula is an important exception. Always follow product-specific instructions and safe storage guidance; neither a date nor a smell test can certify safety.
The date is only one piece of information
You open the refrigerator and find a package whose printed date was yesterday. Throw it away? Use it? The useful first question is what the date actually means. The second is what has happened to the food since you bought it.
At BuyerFood, I want to make that decision less confusing without replacing one oversimplification with another. “Everything is fine after the date” is as unhelpful as “everything becomes dangerous at midnight.” Food type, packaging, refrigeration and time since opening all belong in the conversation.
Think of a label as a set of instructions. The date may be the largest number, but “keep refrigerated,” “use within X days of opening,” and preparation directions can be just as important. Read them together, rather than treating the date as the whole answer.
Decode the common phrases
USDA FSIS describes common voluntary date wording this way: “Best if Used By” concerns peak flavor or quality; “Sell By” helps the retailer manage display; “Use By” is a manufacturer’s recommended last date for peak quality, except when used on infant formula. These definitions are not a universal permission to ignore a manufacturer’s safety instructions. USDA FSIS: Food Product Dating.
| Phrase | What to check next |
|---|---|
| Best if used by | Food type, storage conditions and package instructions |
| Sell by | How soon you will use or freeze the purchase |
| Use by | Product-specific directions; never use infant formula after its use-by date |
Do not translate an Italian label rule word for word onto an American package. Different markets use different systems. This guide is written for US household decisions, with US sources linked so you can check the underlying guidance.
Opening a package changes the question
A distant printed date is not a promise about an opened container. Once the seal is broken, the practical question becomes how long that particular food may be refrigerated after opening. Follow the package’s instructions, including any shorter limit.
Write the opening date on a small piece of tape. “Opened Monday” is much more useful next weekend than trying to remember which shopping trip the package came from. For food you divide into containers, keep enough of the original label to identify the product and its instructions.
This habit also reduces duplicate purchases. If you can immediately see that a container is already open, you are less likely to start a second one and leave the first behind. Store older, still-suitable food where it will be used first, without hiding newer items at the back indefinitely.
Use storage guidance alongside the label
FoodSafety.gov lists refrigerated storage windows at 40°F (4°C) or below, including 1–2 days for raw poultry and 3–4 days for cooked meat or poultry leftovers. Those are household storage guidelines, not extensions granted by a later package date. FoodSafety.gov: Cold Food Storage Chart.
If you bought chicken for a meal several days away, decide on freezing when you unpack it. Do not wait until the date feels urgent. A freezer works best as part of the plan, not as a last-minute place to put food whose history is uncertain.
Keep a refrigerator thermometer inside. A dial marked “3” or “medium” is a setting, not a temperature reading. The question is whether the food has actually stayed cold, including during the trip home.
A normal smell is not a safety certificate
Your senses can tell you that something is unpleasant or spoiled. They cannot prove that an otherwise normal-looking food is safe. A chicken package with a reassuring date and no obvious odor still needs safe handling and proper cooking.
USDA advises discarding perishables left at room temperature for more than two hours, or more than one hour above 90°F. A valid date does not undo that exposure. USDA FSIS: Leftovers and Food Safety.
Avoid “just taste it” as an investigation method. When storage history is unknown, tasting adds exposure without resolving the missing information. The better household system is to make the history visible with dates, simple portions and prompt refrigeration.
A calm decision routine
- Identify the exact food and read the entire label.
- Check whether it is unopened, opened or already cooked.
- Establish how it has been stored, including time away from refrigeration.
- Use product-specific directions and official storage guidance together.
- If it is still suitable but will not be used soon, consider freezing where appropriate.
Keep infant formula outside any general “best by” shortcut: do not buy or use it after its use-by date. If a product is subject to a recall, follow the recall instructions regardless of the printed date.
For next week, choose one shelf or container for foods to use soon. Give those foods actual places in your meals. That small change is more helpful than keeping a refrigerator full of good intentions.
Continue with the leftovers routine for cooling, labeling and reheating cooked meals.
Sources and editorial note
USDA FSIS: Food Product Dating
FoodSafety.gov: Cold Food Storage Chart
USDA FSIS: Leftovers and Food Safety
US editorial draft prepared with AI assistance for Simone Paciaroni’s review. Sources checked September 13, 2026. This preparation date is not a claim of completed expert review. New recipe adaptations have not been kitchen-tested. Follow product-specific instructions and recall notices.