Food Date Marking Calculator
Prep date to discard day and storage rule.
What it does
Date marks turn fridges from guessing games into calendars. Ready-to-eat hazardous food held past a day gets prep and discard dates with seven days total, prep day included. Labels enforce what memory forgets.
The tool above adds six days to the prep date in UTC and prints the discard day with the 41-degree rule. October 10 prepped discards after October 16; off-by-one errors end here.
FDA Food Code date-marking provisions with food-protection guidance carry the seven-day, 41-degree pair with cooling rules in front of it. Freezing pauses clocks under separate provisions; bad cooling voids marking entirely.
Mark everything, log temps, toss the expired. Mystery containers and mixed batches all go regardless of smell. Labels cost pennies; outbreaks cost businesses.
How to use
- Enter the prep date.
- Read the discard-after date.
- Label container with both dates.
- Hold at 41 F or below.
- Discard past-date food.
- Log temps alongside.
Formula
- prepped
- Preparation date (day 1).
Seven-day total includes the preparation day per Food Code date-marking rules. Applies to ready-to-eat hazardous food held over 24 hours. Freezing stops the clock under its own provisions.
Worked example
Example: prepped Oct 10
Soup prepped October 10, 2026.
- Soup prepped Oct 10, 2026.
- Day 1 is prep day; 7 days total.
- Discard after Oct 10 + 6 = Fri Oct 16 2026.
- Hold at 41 F or below throughout.
- Label with prep and discard dates.
Reference table
| Situation | Mark | Discard |
|---|---|---|
| Cooked meats | Prep + 6 days | After day 7 |
| Opened deli | Prep + 6 days | After day 7 |
| Fresh produce cut | Prep + 6 days | After day 7 |
| Frozen first | Per freeze rules | On thaw clock |
Limits
- US Food Code timing. Jurisdictions vary details.
- Proper cooling assumed first.
- Freezing rules sit outside this math.
- Labels need temps behind them.
Common mistakes
- Counting prep day as day zero.
- Marking badly cooled food.
- Trusting smell over dates.
- Mixing batches under one label.
- Holding above 41 F.
Try it yourself
Quick checks. Answers sit tucked under each question.
Prepped Mar 1, 2026?
Mar 1 + 6 = Sat Mar 07 2026. Discard after that date at 41 F or below.
Prepped Jun 1, 2026?
Jun 1 + 6 = Sun Jun 07 2026. Day 1 is prep day in the 7-day count.
Questions
What must be date marked?
Ready-to-eat potentially hazardous food held over 24 hours gets marked with prep and discard dates. Day 1 is prep day; discard after day 7. Freezing pauses the clock with rules.
How is the discard date figured?
Prep day plus six: October 10 prepped discards after October 16. The seven days include prep day itself, a common off-by-one trap.
How cold must it stay?
41 F or below the whole time with calibrated thermometers. Warmer holds void date math entirely.
Does marking fix bad cooling?
No. Date marking assumes proper cooling first; food that cooled wrong never earns seven days. Cool right, then mark.
What if the date passes?
Discard it. Past-date food, mystery containers, and mixed batches all go. The trash costs less than the outbreak.
What labels do inspectors want?
Prep date, discard date, and contents on every container, plus temperature logs behind them. Inspectors read labels first.