Some lore on eggs that might include some bits that are actually true.

"Buying at the gate" as mentioned above would not seem to assure freshness. When grand daddy sold eggs to the creamery we gathered about a dozen and a half per day, and they were stored in, as I recall, crates holding 16 dozen. The eggs went in to the buyer about once per week. A place that can sell you more than a scant dozen when you show up at the gate probably isn't your "little ol' family farm." It's an egg factory.

Fresh laid eggs are coated with a film of "mucous" from the hens' "delivery canal" and the film helps to prevent air from permeating through the shell. Fresh-gathered eggs should NEVER be washed, since that lets the air get in and the eggs will spoil much faster. Most small farms might use a scrap of "steel wool" to remove soil (farm hens do crap in their nests sometimes) but washing was never a good idea.

A "modernization" that appeared for a while where small farmers sold to a "collector" permitted washing the eggs when gathered, provided that they were immediately dipped in a "sealer" to make the shells "air tight." The sealer commonly used ca 1945 - '50 was the same "water glass" that was a main component in the radiator "leak stopper" used in old autos. [That stuff is now considered mildly toxic and is very hard to get for any use (in the US) - which is unfortunate since it has numerous other uses where it would still be appropriate.]

When small farms still could sell their eggs when they went to town to do their "Saturday night shopping and socializing," few farms had much in the way of "cold storage" beyond a cool corner in the pantry or sometimes a root cellar, but "cool room temperature" was generally considered good enough for about a week, by the buyers. The buyers would, of course have refrigerated storage for them (since about 1935 in my area).

The "factory eggs" sold by most grocers are delivered to the stores fairly quickly, but the eggs may be "a few days" old by the time they get there. Since the cartons are required to be marked with an "expiration date" (sell by date) here, one sometimes sees two (rarely three) different dates in the bin in larger stores. In larger stores at least, it would appear that new batches come in at about 3 day intervals, based just on the "steps" from one date to the next. At smaller stores the turnover may not be quite as fast but it's rare in my area to see dates more than a week apart in the same bin. It might be inferred that the "shelf time" in the point of sale stores probably is not much more than about a week, although I haven't found a legal limit stated. Any limits that do exist would be set by the state, so they may vary.

John