quicko: expiration dates

Having been a gallon-a-day family when it came to milk, I manage pretty consistently to be a gallon-a-week girl. A gallon would suit me wonderfully, if only I could find one. Instead, I'm stuck with 3 liters, which is more or less comparable. The part that's not comparable is the expiration dates. To begin with, American milks (note: if I have any students reading, milk is uncountable. Don't worry about this, nor try to copy it.) usually come with a "sell-by" date, which, granted, is somewhat different from an out and out "expiration" date. But when they say expire, man, do they mean it. By the day of, that milk is starting to smell (quite often a day or two early, as well) and let another day or two go past and it'll outright reek. So, even when you look in the fridge and think, plenty of milk, all's well, well, it really isn't. Which is to say, please excuse me as I run to the store. I seem to be out of milk.