So your eggs are close to or past their recommended use by. Or maybe you have your own chooks and you're not sure how old your eggs are. Before you throw them out you can test them to see if they are still good. This is an old trick your grand mother would have used.
First take your egg. Funny face drawn on is optional (done with a Chinagraph / wax pencil)
Gently place it into a glass of water.
Make sure you choose a glass big enough for the egg to sink to the bottom.
If it sinks, it's a good egg and it's fine to eat.
If it floats, it's a bad egg so do not eat it!
It floats because of the gas created as it decomposes.
I usually test a whole carton to see if any need to be disposed of, then retest them as I use them. I break our bad eggs directly into the compost bin.