The length of time will depend on several factors including, the breed ecotype, the period within which the mother hen spent with the chicks after hatching(imprinting), level of nutrition, social environment i.e any cock within the enclosure, season of the year(during cold season they take longer than dry season). On average other factors remaining constant, they tend to take from between 2weeks to 1 month. Remember after broodibg chicks, birds gets into molting period which must be completed before the cycle of laying starts again.