Properly labeling foods—specifically those deemed as Potentially Hazardous Foods (PHF)—with their “use by” or “discard” dates is the best way to take the guesswork out of their shelf life, and it all starts with knowing Day 1.
To know what Day 1 is, you’ll need to have a bit of background information, first: All refrigerated PHF foods must be used within seven days of preparation, and according to the FDA Food Code, they must be marked with their discard date if they’re not used within 24 hours.
According to the 2013 Food Code Section 3-501.17(A) and (B), Day 1 denotes the day on which the food was prepared. If a prepared food contains ingredients that were made on different days, Day 1 for the final product would be the date of the earliest prepared item that was used to make it. Then the clock starts ticking until Day 7, which is when the food should be thrown out.
Of course, this protocol could vary state by state. Says Raymond Duffill, Sr. Regional Food Safety Specialist, US FDA, “Since some states’ regulations do not include date marking as a requirement, managers should check with their local health department for their own mandates.”