I go weeks and even months sometimes past sell by date (not expiration date, btw.) If you float the eggs in water you can tell if they are still good or not. If they sink to the bottom of the bowl, they are still good. If they float on top, they are bad. I did this for 3 eggs over the summer....6 weeks past sell by date. I wanted to make cookies and I needed 2 eggs. First one dropped, the 2nd clearly floated, the 3rd sank. There was a clear distinction between the sinker/floater.