Egg should not be shipped older than 2 days
Normally, that would be true, however, out of necessity, I have shipped eggs that were a week old due to only having two hens in one certain breed (with knowledge of the buyer, of course). Since each hen only lays at most, one egg per day, sometimes it cannot be helped. You can hatch eggs that are up to two weeks old with little difference in hatchability, as long as they are treated well by the P.O. and the breeder birds are healthy and the eggs good quality in the first place. It seems to have no real bearing on the hatches, as arabookworm's hatch seems to indicate.
Normally, that would be true, however, out of necessity, I have shipped eggs that were a week old due to only having two hens in one certain breed (with knowledge of the buyer, of course). Since each hen only lays at most, one egg per day, sometimes it cannot be helped. You can hatch eggs that are up to two weeks old with little difference in hatchability, as long as they are treated well by the P.O. and the breeder birds are healthy and the eggs good quality in the first place. It seems to have no real bearing on the hatches, as arabookworm's hatch seems to indicate.