StillTasty.com has comprehensive information about how long you can keep thousands of foods and beverages. Many foods are still safe to eat beyond the expiration date—especially if the date is considered a best if used by or sell by date. Foods will generally smell, taste, or look off if it's not safe. Frozen foods are safe indefinitely, but they will start to lose quality the longer it is stored. Many fresh or prepared foods are labeled with a ‘Sell-By’ date as a guide for how long the item should be displayed for sale before quality deteriorates. Items are generally safe to eat after this date but may begin to lose flavor or eye appeal. Information on sell-by, use-by, best-by and other dates and how to calculate the actual shelf life of food. Shelf life depends on the degradation mechanism of the specific product. Most can be influenced by several factors: exposure to light, heat, moisture, transmission of gases, mechanical stresses, and contamination by things such as micro-organisms. This shelf life extension applies to all batches that have been released to the U.S. market, and that have been held in accordance with the manufacturer’s storage conditions. The meaning of SHELF LIFE is the period of time during which a material may be stored and remain suitable for use; broadly : the period of time during which something lasts or remains popular. Find the shelf life of any food, medicine, cosmetic, or household product. Authoritative data from USDA, FDA, and manufacturer guidelines. Enter the manufactured date and the expiration date into the Shelf Life Calculator. The calculator will evaluate the Shelf Life. This can also calculate the date at 25%, 50%, and 75% of shelf life remaining. On the other hand, shelf life refers to the period of time during which a product can be stored before it starts to deteriorate in quality. While the expiry date is a fixed point in time, the shelf life can vary depending on how the product is stored and handled.