班固写的《汉书·食货志》上有下面的记载：“冬，民既人；妇人同巷相从夜绩，女工一月得四十五日。”
In the chapter " Foods and Goods " of The Chronicles of the Han Dynasty , the great historian Ban Gu states : " In winter people stay indoors . Women get together to spin hemp threads at night . They manage to work forty-five days in a month . "
食货志