Sentence:  date of laying , length of incubation period , number of chicks reaching the first week , second <WSD>week</WSD> , fifth week , weight of hen , size of rooster 's wattles and so on , all scrawled out in a hand that looked more Chinese than English , the most jagged and sprawling Alex had ever seen . 
Meaning of the word marked with <WSD> tags:  any period of seven consecutive days