How long does it take an fowl to hatch an egg?

Hens begin laying at 18 ? 20 weeks of age and a healthy chicken will lay about one egg a day. A hen does not need a rooster to lay eggs and eggs are produced in response to day light patterns. The eggs we buy in the store are not fertilized (they don?t hatch). The size of the egg is dependant on the age of the hen. Older birds lay larger eggs."