Storing Fresh Fluid Milk: Milk should not be left out at room temperature. Pour milk to be used into a serving container and return the original container to the refrigerator. Do not return unused milk that has been sitting out to its original container where it could contaminate the remaining milk.
Say goodbye to days of throwing out your half-eaten tub of yogurt, because this is another dairy product you can eat after its package labels it expired.. Open yogurt will spoil sooner than unopened yogurt, but sealed yogurt will usually last one to two weeks past the sell-by date.
You're not exactly looking at an expiration date in the sense that the milk is going to die on that day- it's more like a last day to sell by date. As a general rule, unopened items are safe for up to 7 days after the date printed on the package. If it's opened, though- you are on your own time and it's anybody's guess.