how long can I keep eggs for after there sell by date.
two weeks or so in a cool, dry place or perhaps a bit longer in the fridge. assuming they're very fresh when you bought them!
This is a really handy test for determining if eggs have gone bad: Place them in a bowl of water. If they float to the top, throw them out! If they stay at the bottom -- even with just one end touching, they're okay. Also, if you happen to crack one open and it smells funky, get rid of it.
Eggs do have a long shelf life. 3 to 4 weeks under refrigeration should be fine.
Referigerated ggs rarely go bad, they mostly just shrink in the shell and lose loft. Like Kristen said, you will know by the smell if it is bad.
Good question - learned something I didn't know. According to http://pubs.ext.vt.edu/348/348-960/348-960.html "Use eggs within 3 to 5 weeks of the “pack date” listed on the carton (1 to 365 representing pack date day within the year)."
Older eggs past the "Sell by date" are perfect for making boiled eggs as they peel much easier. They aren't so good for making sunny side up eggs, or poached eggs as the yoke tends to break. They're still good for most applications for weeks, as mentioned.
I think the nose knows!