Here’s a superbly-kept secret: all those dates on food products—sell by, use by, best before—almost none of those dates indicate the safety of food, and generally speaking, they’re not regulated in the way many people believe. The current system of expiration dates misleads consumers to believe they must discard food in order to protect their own safety. In fact, the dates are only suggestions by the manufacturer for when the food is at its peak quality, not when it is unsafe to eat. 

Read it here: http://www.nrdc.org/food/files/dating-game-IB.pdf