Free tool
Best-by and date label decoder
Choose the wording printed on your package to see whether it is about safety or quality. Julian pack codes are converted to a calendar date.
Pick a label to see what it means.
What each label means
- Best if used by — guidance on peak quality. It says nothing about safety.
- Use by — the final day suggested for top quality. On infant formula, it is a safety date required by federal rules.
- Sell by — tells the shop when to rotate stock. At home, start counting storage time from the day you bought it.
- Freeze by — get it into the freezer by this day to hold on to quality.
Reference: USDA FSIS, "Food Product Dating".
Questions & answers
Can I still eat food once the best-by date has passed?
In most cases, yes, as long as it was stored correctly. Best-by refers to quality, so let smell, appearance and taste guide you.
Does the law require any date labels?
Under US federal rules, infant formula is the only product that must carry a use-by date. Manufacturers choose every other date themselves.
How do I read a Julian date code?
It records the pack date as a day of the year (001–365), usually with a digit for the year in front: 3215 means day 215 of a year ending in 3.
What is a sell-by date for?
It tells the retailer how long to keep the item on display. Past that date, you can still keep it at home for its usual fridge time.
Other calculators: Leftover calculator · Freezer time calculator · Thaw time calculator · Left-out checker
Figures here are drawn from USDA FoodKeeper plus FSIS guidance. Data re-checked November 2026. How we check our numbers · Spotted an error? Tell us