A use-by date is the last day the manufacturer recommends using the food. Use or freeze the food by then.
USDA describes use by as a peak-quality date that is “not a safety date except when used on infant formula.” But the grocery industry's voluntary standard and California's 2024 date-label law both use “use by” for foods that should be thrown out after the date. A package doesn't tell you which meaning its maker had in mind, so the safe habit is to treat every use-by date as a deadline.
Same two words, different definitions
Most date phrases have one loose meaning. “Use by” has several, depending on who you ask:
| Who says | What "use by" means | Binding? |
|---|---|---|
| USDA FSIS (consumer guidance) | "The last date recommended for the use of the product while at peak quality. It is not a safety date except when used on infant formula." | Guidance. Dates on meat and poultry are voluntary. |
| FDA, infant formula (21 CFR 107.20) | The date through which the formula will contain at least the labeled amount of each nutrient and be of acceptable quality | Yes. Required on every container. |
| GMA and FMI voluntary standard (2017) | "Applies to perishable products that should be consumed by the date on the package and discarded after that date" | No. A voluntary industry initiative. |
| California AB 660 (food made on or after July 1, 2026) | "USE by" or "USE by or Freeze by" indicates the safety date. CDFA: a safety date indicates when a food "is no longer safe to eat." | Yes, for how dates must be worded on food sold in California |
| Food Date Labeling Act of 2025 (proposed) | "USE By" would be the uniform discard-date phrase: the end of shelf life, after which the maker advises the product not be eaten | No. Introduced in Congress, not law. |
FDA hasn't picked a side. In its 2019 letter backing Best if Used By for quality dates, the agency noted the industry recommends “Use By” for safety and said it “is not addressing the use of a ‘Use by’ product date label for safety reasons at this time.”
Why a “quality” date can still be about safety
When USDA finalized its date-labeling fact sheet in 2019, a meat industry trade association objected. It said the shelf life of refrigerated ready-to-eat meat and poultry is often set to control Listeria monocytogenes, not flavor, and that the industry “often applies a ‘Use By’ date to ensure refrigerated RTE product safety.”
FSIS kept its wording but agreed with part of the point: “some establishments may use date labeling to manage safety of refrigerated RTE meat and poultry products,” though not all do. For products made with an antimicrobial agent or process to limit Listeria, FSIS “recommends but does not require” a use-by date.
That's the gap. A use-by date on hot dogs or sliced turkey might mark the end of peak flavor, or the end of the shelf life the maker validated for Listeria control. The label looks the same either way. Listeria can grow at refrigerator temperatures, and CDC lists unheated deli meat, cold cuts, hot dogs, refrigerated smoked fish, refrigerated pâté and meat spreads, and premade deli salads among the higher-risk foods. The people most at risk are pregnant women, newborns, adults 65 and older, and people with weakened immune systems.
What to do with a use-by date
- Use it or freeze it by the date. Freezing at 0°F (-18°C) keeps food safe indefinitely, according to FDA. The quality after thawing depends on how fresh it was when frozen. If the label says
USE OR FREEZE BY, it's one deadline for both. - Once opened, use whichever comes first. The date assumes a sealed package. FDA's storage chart gives opened lunch meat 3–5 days and opened hot dogs 1 week in the fridge, even if the printed date is later.
- Keep the fridge at 40°F (4°C) or below. A use-by date assumes proper refrigeration all the way home and after.
- Mishandled food doesn't get the date. USDA says perishable food left out more than 2 hours (1 hour above 90°F) shouldn't be eaten, even if the date hasn't arrived.
- Past the date? Don't eat refrigerated ready-to-eat foods. For other foods, a date that passed yesterday on something that was kept cold is lower risk, but there's no way to know how the maker set it. When in doubt, throw it out, and never taste food to check.
For raw meat and poultry that has only a sell-by date or no date, the clock is days from purchase instead. See what sell by means and the storage times for deli meat, chicken and ground beef.
A use-by date only helps if you see it in time. FreshScan reads the date off the package, marks it as a use-by date, and reminds you two days ahead: early enough to cook it or get it into the freezer.
Free on theApp StoreUse by vs best by
Best by is the looser of the two. It marks peak quality, and shelf-stable food with a best-by date is often fine well after it. Use by is the one to respect. Under California's law, the two are now worded to make that difference obvious: BEST if Used by for quality, USE by for safety. See best by explained, the side-by-side comparison of every date label, and California's date label law.
Questions people ask
Can I eat food one day after the use-by date?
The cautious answer is no, especially for refrigerated ready-to-eat foods like deli meat, hot dogs, smoked fish and prepared salads. USDA's general guidance treats use by as a quality date, but some manufacturers set it to control bacteria such as Listeria, and you can't tell from the package which kind it is. Use or freeze food by its use-by date.
Is a use-by date the same as an expiration date?
In practice, close. Neither has a single federal definition for most foods. Both are dates the maker wants you to use the food by, so treat an EXP or expires date the same way you treat use by.
Can I freeze food on its use-by date?
Yes, if it has been refrigerated properly up to then. FDA says food kept frozen at 0°F (-18°C) stays safe indefinitely. Freezing pauses the clock but doesn't reset it, so thaw it in the fridge and use it promptly.
What does UB mean on a label?
UB is the short form of "USE by". California's AB 660 allows UB on packages too small for the full phrase, for food manufactured on or after July 1, 2026, and the proposed federal Food Date Labeling Act uses the same abbreviation.
Does the use-by date still count after I open the package?
Use whichever comes first: the use-by date or the opened storage time. Opened lunch meat, for example, keeps 3–5 days in the fridge according to FDA, even if the printed date is a week away.
Sources
- Food Product Dating — USDA Food Safety and Inspection Service
- Availability of FSIS Food Product Dating Fact Sheet (Federal Register notice, April 9, 2019) — USDA FSIS. Includes FSIS's response on "Use By" dates and Listeria control
- Letter to the food industry on "Best if Used By" date labels (May 23, 2019) — U.S. Food and Drug Administration. Describes the 2017 GMA/FMI voluntary date-label standard
- 21 CFR 107.20: Directions for use (infant formula "Use by" date) — Code of Federal Regulations, via Cornell Legal Information Institute
- AB 660 (Irwin, 2024): Food and beverage products: labeling: quality dates, safety dates, and sell-by dates — California Legislative Information
- Food Date Labeling — California Department of Food and Agriculture
- H.R.4987: Food Date Labeling Act of 2025 (introduced) — Congress.gov
- Preventing Listeria Infection — Centers for Disease Control and Prevention
- How Listeria Spreads — Centers for Disease Control and Prevention
- Refrigerator & Freezer Storage Chart — U.S. Food and Drug Administration