it's a matter of some debate em, but i keep mine in the kitchen, never in the fridge, and sometimes they sit there for weeks before being used, well past the date stamped on them. never done me any harm.
others would throw their hands up in horror and say they need to be refrigerated and eaten by the date stamp.
think i have some with august stamped on them, so will have to check, i wasn't sure if it was the eggs that tasted a bit strange, or that they are free range, sounds daft i know. Had soft boiled eggs for the first time in ages, and i must say that they were a pleasant change and not overdone.
There is little doubt if an egg is rotten.....it really stinks and you would be quite unable to even think of eating it.
(I use mine ages after the sell-by date but I do keep them in the fridge. I take them out for a while to warm up if I'm using them for baking.)