Quote: Mostly correct. I had no issues with the 14-18 day old eggs, but only got one older than that to hatch. These were peafowl eggs, so it might be different for chickens, guineas and ducks.
Peafowl normally lay every other day until they have 4-6 eggs then they sit. Some of my ducks can take over three weeks to make a nest. If I decide to hatch any pea eggs this year I will not let them sit for more than two weeks.
-Kathy