Seven days. That's it.
Once you've boiled eggs, they have just one week until you should think twice about eating one. (That's assuming they've been stored in the fridge shortly after being boiled.) And if that hard boiled egg was peeled before being refrigerated, that knocks two more days off of its shelf life. Surprising, we know, especially when you consider the fact that eggs are safe for consumption for up to five weeks after purchase.
Even though they look a lot like regular eggs, they don't as long because cooking the eggs dissolves the cuticle, a naturally occurring waxy protective layer found on the shell. It's the cuticle that gives eggs their long shelf life. While most of it is washed off during the packaging process, the rest of it disappears with boiling. Without this layer, porous egg shells are left open for bacteria to contaminate the contents of the egg more easily. And we all know that contaminated eggs are bad news.
If that thought has got you nervous about the freshness of the eggs currently in your fridge, you can always give the water trick a try. Place the egg in a bowl of water and if it floats to the top, DO NOT EAT IT. It will make you very, very sick. If the egg sinks and lays on its side, you're good to go. But if it sinks and stands up, make a hard boiled egg out of it -- these eggs are the easiest to peel.