Reader Leo writes in with some helpful information that will allow you to avoid stale candy:
I work at a small-volume store in the midwest, and the other day my supervisor asked us to check all of the candy in the checkout lanes to see if it had expired. M&M Mars and Hershey brand candy both had different, indecipherable codes on the back which tell the expiration date. After calling the 1-800 number and finding out what the codes meant, we discovered that most of our candy stock was expired by a year or more. We even found candy that went bad from 2004. I figured I should share the codes, so people won’t buy expired candy, because it’s out there.
For M&Ms and Mars candy, there’s usually a 10 digit code of numbers and letters, but you only need to worry about the first three. The first number is the last number in the year (8 means 2008, 7 means 2007, etc) and the next two numbers stand for the week of the year (so, a number like 804 would be the fourth week of 2008: February 2008)
For Hershey’s candy, there’s a 2 character code for the month and year. The year is like the other code, with the number being the last number in the year, the second character is a letter that represents the month. A = January, B = February, and so on. So a code like 9A would mean that the candy expires January of 2009.
Stale candy isn’t really “expired” in the sense that milk and other perishable goods “expire.” In this case, the candy is merely stale and isn’t as tasty as it should be. Still, why buy old candy?