well a lot of the eggs you get in the supper markets are a lot older than you would ever expect. Like i would not be surprised at all if i was told they were a year old. you can however tell by getting a bowl of cold water and put the egg in the bowl of water, if it floats toss it. if it sinks its good till it floats. if it looks like it wants to float, bake with it. you should be able to find this on the Internet somewhere, i just remember watching "The Dive" that had dumpster divers and what they did to tell if the eggs they got out of the dumpsters were good or not. hope this helps.