Have you ever noticed how some food items will have expiration dates, whereas others simply have use by dates? Did you ever stop to consider that their is a reason beyond simple dialectic choice that determines which phrasing is used?
As it turns out, their is a purpose in the phrasing. Items with a use by date are marked as such, because the product has the possibility of staying good beyond this date, however it is recommended that it be used by a specific date in order to assure optimum freshness and usability.
An expiration date, as should be made obvious by its precarious position on milk, eggs, and cheese is the date by which foods are expected to go bad. As most people know just because the day of expiration has arrived does not necessarily mean that the milk is bad on that day, in fact sometimes the milk does not sour for a few days following the date of expiration. This is where the smell test comes into place. Of course if there is ever any doubt about a products safety in terms of consumability based on smell, taste, or consistency of texture its probably best to just throw it out and buy a fresh version.
My favorite tip on how to use up the last of the milk before it goes bad:
Pick up a few packages of Martha White Muffin Mix and make a bunch of breakfast muffins for the week or weekend. Add 1/2 cup milk to mix stir and pour into 6 muffin tins, place in oven at designated temperature and time according to packaging and your done. You got to use up the last of the milk before it went bad, and you have a tasty breakfast or snack for the week.