Store employees use 'open dating,' the calendar date on food packages, to decide when to pull an item from the shelf. For consumers, the date indicates freshness or quality. Use both the date itself and the phrase in front of the date, such as 'use by' or 'best by' to make your decision on which milk carton or cookie package to choose.

Tips

Take an extra second or two when taking foods off the shelves at the store so you can bring home the item with the longest use-by or best-by date available.

Federal law doesn't require manufacturers or stores to use opening dating, except for infant formula, but some states have their own requirements. If manufacturers choose to use dates, they must indicate the month, the day and a phrase explaining the date:

• Sell by means that the store will pull the item after that date passes. You can still use the product after the date passes once you get it home.
• Best by, Best if Used Before and Use by indicate that the quality of the product will suffer after the date passes. Breads or cookies will turn dry, granola bars may lose their crunch and a square of baking chocolate may turn whitish, but none of those conditions make the food unsafe.

Tips

Eggs are in a class by themselves when it comes to dating. A three-digit code on the carton represents the day the eggs were packed, with January 1 indicated as 001 and December 31st as 365. The sell-by date can be up to 45 days beyond the pack date, but you can still use the eggs safely after that time for an additional 3 to 5 weeks, according to the University of Nebraska-Lincoln website.

Open dating doesn't tell you whether or not your food is safe. According to a 2013 report by the Natural Resources Defense Council, Americans waste 160 billion pounds of food each year, mistakenly throwing away products because they believe that open dating indicates whether or not a food is safe to eat.

Because food within a 'use by' or 'best by' date can still be unsafe due to improper storage either at the store or at your home, learning about food safety is essential. You can do this in a number of ways:

• Refer to a Food Keeper's Guide, such as one published by the Food and Marketing Institute, to tell you how long a certain food stays safe at room temperature, in the fridge or in the freezer.
• Educate yourself about food safety, including what temperature to keep your refrigerator adjusted to, how long to cook foods for or how to properly wash foods. The U.S. Department of Agriculture publishes a wealth of information on the subject.