The vast majority of expiration dates are bogus - here's how long your food is still good
But most expiration dates are largely made up. According to The National Resource Defense Council, the "sell by" dates do indicate not whether foods are safe to eat - they simply tell you when food will reach its limits for "optimal quality."
The handy website StillTasty compiles data from sources including the USDA, the FDA, and the US Centers for Disease Control and Prevention, as well as food manufacturers themselves. The site provides helpful tips on when to dispose of hundreds of household goods.