Question: how do you know if an egg is old

I know how to check if they’re bad, but I was wondering how long eggs last. I know you can buy them in packs and it says the sell by date.<br><br>But if you gather eggs from your chickens, how do you know? Or, I guess, how do you know when they’re at their best quality?<br><br>I’ve read online that they’re good for 5-7 weeks, but that was for store bought eggs.