Since 1972, FSIS has required poultry products to include a date of packing, either as a calendar date or a code (9 CFR Section 381.126). FSIS has permitted the use of a sell-by or use-by date in lieu of the required date of packing.

There is no regulation requiring meat products to have a calendar date. However, if a federally inspected establishment has voluntarily placed a calendar date on meat products, such a date can not be removed or changed by a retailer while the product remains in its original packaging. If a calendar date is used on labeling for either meat or poultry, a phrase explaining the meaning of such date, in terms of "packing" date, "sell by" date, or "use before" date, must be right next to it.

A food retailer may not modify these "packing/pack" or "sell-by/use-by" dates on the original packaging of meat or poultry products packaged under Federal inspection, even if the date has been placed voluntarily. However, if a retailer places a calendar date on meat or poultry products that did not bear a date originally, there is no Federal regulation that would prevent a retailer from changing the date on products that remain wholesome. State or local jurisdictions, however, may have a requirement that bars changing these dates at the retail level.