All about eggs

How long to keep them
Eggs in the shell are safe to eat up to five weeks after the sell-by date, found on the short end of the carton.

Numbers on the carton
The carton information contains the packing date and the plant number.

The three digit number in the middle tells you the Julian packing date. Julian dates count the days by number. On January 1 the Julian date is 001. On December 31, the Julian date is 365.

The Plant number is also on the carton. This is a four-digit number beginning with the letter P. You should be able to look up the plant at the following link: https://apps.ams.usda.gov/plantbook/Query_Pages/plantbook_query.asp
However, in a recent test of the link, no plant number returned a valid result. This may be fixed in the future.

Egg grades
The carton could also have the egg grade, but not necessarily. If you don’t see it on the carton itself, a USDA shield may appear on the carton specifying the grade.
Grade AA: Egg white is thick and firm. Yolks are high, round and practically free from defects. Clean, unbroken shells.
Grade A: Whites are reasonably firm. Yolks are high, round and practically free from defects. Clean, unbroken shells.
Grade B: Whites may be thinner. Yolks may be wider and flatter. Shells unbroken, but may show slight stains.