This question comes up a lot. Cornell University has a good article here.
For best results, set eggs within 1-3 days from the time they were laid. There is an average loss of about 3% hatchability for eggs stored 7 days before setting, and about 10% loss for those stored 14 days.
For best results, set eggs within 1-3 days from the time they were laid. There is an average loss of about 3% hatchability for eggs stored 7 days before setting, and about 10% loss for those stored 14 days.