This Is Eggterrific
There are a number of ways to test if your eggs have gone bad. You can put them in a glass of water and see if they float. If they do, that means the air cell has enlarged significantly, and the egg has gone bad. But I bet you didn’t know that there are ways to keep your eggs fresh for longer.
Source: Reddit
Fill a container of salt and place your eggs small-side down. Make sure to keep the container in a cool, dark place. But not too cold! Eggs can rot faster if they are exposed to freezing temperatures. By preparing your eggs this way, they will stay fresh for anywhere from eight to ten months.