Best if used by, sell by, expiration dates -- what do these dates all really mean? A new proposal in Congress aims to clear up the confusion when it comes to food. 

Two lawmakers introduced a bill Wednesday that would set a national standard for date labels on food. 

20 states actually restrict the sale of certain foods past the date marked on the label, even if the date is referencing quality. The USDA says the average American throws out 36 pounds of perfectly good food a month. 

In addition to creating a national standard, the proposal would also distinguish between dates referencing safety and dates referencing quality.