What does the date on eggs mean if it does not say sell by or expires by in the United States? I have several cartons of eggs that have a date stamp but the date stamp does not say, sell by, expires by or best by. It's just a date. By the way the date is in the future so I know it is not a pack date of when the eggs were packed. If I knew that I would be OK.

What is the default if the date is just a future date? Should I assume it is an expiration date and it's time to toss them out after that or should I assume it is a best buy in which case it is good for another 2 weeks or so? I assume on eggs there is no such thing as best by because you need to know or be able to figure out when they will expire so you can toss them out.

The date appears as follows "May 29 11:45" 121 P1008 L6". I know you will be tempted to say pack date but May 29 is in the future. Should I eat them all by May 29 or do I have the standard 2 weeks after a sell by date?
In the US, the most important thing to look for on the carton is the number which shows the day of year that the eggs were packed. If the number is 1, that's January 1st. If it's 365, That's Dec 31st. In other countries the system may be different, so find out what system in your country indicates the pack date, if possible. Note: apparently some states in the US don't regulate this, so you would have to see what your state's protocol is, if not. All the good states do, and the others can go suck an egg. 

Eggs last a very long time (a few months at least) properly refrigerated and are safe to eat long after the sell date. The egg will lose water, and the air bubble in the end of the egg will continue to grow, so if you put the egg in water and it floats, it's pretty old, but can generally still be eaten if the eggs is not crazy old. 

The membranes will also thin over time, making the yolks easier to break if you're trying to separate them or use them for sunny-side up eggs, e.g. The whites will also thin and the thicker part of the whites won't be as pronounced from the thinner parts. 

Some recipes actually call for aged eggs. Also note that in the US eggs are washed and the outer membrane is removed, so they must be refrigerated. In some other countries the outer membrane is left on and the eggs can be stored safely outside of the refrigerator.