welll i dont know about the outside of the egg but inside its about 2 weeks
21 days from the day the hen sets. She may not actually sit on the eggs until she has gathered a clutch of 4 to 15 eggs. Other hens may add to her nest so all the eggs may not be hers.
21 days
Amphibian lay their eggs in water and hatch in water.
Egg formation takes 24-26 hours inside of the chicken. Chicks hatch from eggs after 21 days.