Eggs can keep for a very long time! As they get older, their risk of going bad does increase. If your eggs are rather old and you question their freshness, simply test them before you crack them open.
Simply fill a container with enough water to float an egg and then set the eggs you wish to eat in the container. If an egg has gone bad, it will ferment and then float in the water.
Good eggs sink, bad eggs float! If it floats, dump it without breaking the egg open (it will stink up your entire boat). If it sinks, break it open into a bowl and visually inspect it. If it was good, add it to the recipe; if it was bad, it can be disposed of without contaminating the rest of the good eggs.