how old can eggs be for max fertility?

[Minky]

I am turning 3 times a day (sometimes more) and keeping in my damp and cool cold cellar.... I will set them on Easter Monday... April 13.... I have a few nice eggs from fav hen from March 29, 30, 31.... is 15 days too old?

 

[nchls school]

I am turning 3 times a day (sometimes more) and keeping in my damp and cool cold cellar.... I will set them on Easter Monday... April 13.... I have a few nice eggs from fav hen from March 29, 30, 31.... is 15 days too old?

For best results it's best to use eggs two weeks old or less. Once eggs get to around two weeks viability goes down. This does vary with breed and specie. My serama eggs lose viability quickly at two weeks. My phoenix lose viability at three weeks. I've had turkey eggs over a month old form and hatch. Try it, most likely the eggs will develop and hatch out just fine. Good luck.