Using that well known term "common sense" as a criterion, Genie, your original post seems to have got it right and I suspect you'll have shuffled off the mortal coil before getting better definitions out of officialdom.
Some responses that come to mind include
Many years ago I had the need to look up info on the storage of milk. Details are hazy but I seem to recall that fresh (pasteurised but prior to the current fad for homogenisation) could be stored in a fridge and still be drinkable for a week. However, the vitamins in it would denature rapidly and not be worth the candle after about 2.5 days; the casein would last more or les forever. The relative importance of such variables would be used in any calculations of the dates displayed on the packing. Of course you could freeze milk; while it might be useable for yonks (because of the butterfat, sugar and casein contents) the vitamins would have been rendered useless. leaving the milk useful for flavouring coffee but with little other value.
More recently (but still many years ago) I spent a year at Mawson, Antarctica. In his second trip to the Antarctic Douglas Mawson had struggled back from a sledging journey just in time to see the ship leaving to return to Oz; he spent most of the next year at the base (Commonwealth Bay) with some others who'd remained in case his party had been delayed and they were all picked up the following summer.
The point of that anecdote is that Australia's Antarctic Division has, ever since, always maintained a full years' provisions in reserve at each of its mainland bases. We took down a year's worth of food, stacked it in the various storage locations and, for our year, lived on what had been taken down by the previous year's expeditioners the summer before. That meant that every item was at least a year old at the beginning of our start on it. Given the nature of logistics, some of the nonperishables might have been in storage for six months before leaving Australia. We used lots of multivitamin tablets.
So I've always taken my own view of the dates displayed on food packages, helped along with the sort of training one gets with a good university education in biological sciences. Fooles is right with his "'preserving' with salt, sugar, honey, drying has worked for centuries - it's only the frenzy of 'refrigeration' that has brainwashed people" but there are caveats because of the availability of refrigeration in wealthy communities.
For salt or sugar to be effective at inhibiting bacterial and fungal growth they need to be present at levels high enough for the osmotic gradient to draw water out of any unwanted cells that might otherwise grow there. Such levels of salt are frowned upon by cardiologists and the "low carb" fashionistas wax ridiculously eloquent over the required levels of sugars. This means that items that used to be storable 'forever' when containing traditional levels of salt or sugar now need to be refrigerated if you want to beat the bugs to the goodies.