It depends on how often they're collected, how they're handled, and how they're stored.
I collect eggs 1-2 times/day, do not wash them, and refrigerate them right after collecting them. They last at least 3 months in the refrigerator, but I've read that they could last 4-5 months.
I choose not to wash them, as I want to retain the "bloom" on the egg which acts to keep in moisture and deter bacteria.
I collect them at the end of the day and they go right into the fridge, I do not wash them either. I think I have some in there since December, maybe November. Are they good to eat still?
They should be OK, but just to be safe, crack each egg into a small bowl first before adding to other ingredients. If there's no "rotten egg smell" (sulfur smell) the egg should be fine to eat. They obviously won't be as fresh, but they should still be OK to eat. You may notice that the white and yolk are not as firm as in fresh eggs; that happens during long-term storage.