How long can an egg sit in the coop and still be good?

[J&D Chickens]

Are you in that big of a need for the egg that you found? If you have a good bit, just get rid of it. But the float test is good. If you get them soon, all will sink. If it's old, it will float. We normally get our eggs every 2 days. But if you think it could've been there for a while, just toss it. Not worth it.