They don't mean as much as many people think they do. Most food is still edible after the expiration date but may not be very tasty. (Of course, lots of packaged food isn't much good before the expiration date, but that's another question).

Most people are surprised to find out that:

  • Stores are not legally required to remove food once the expiration date has passed. They are strictly "advisory" in nature.
  • Dating is not federally required, except for infant formula and baby food. States have varying laws. Most states require that milk and other perishables be sold before the expiration date.

The major codes are:

  • Sell byDon't buy the product after this date. This is the "expiration date."
  • Best if used byFlavor or quality is best by this date but the product is still edible thereafter.
  • Use by This is the last day that the manufacturer vouches for the product's quality.

Want to know more? See David Wood's story, Nothing Simple about Food Dating.