In the bamboo manuscripts unearthed from the Zhangjiashan 張家山 Han tomb, the term geng 更 denotes the work shift of state laborers. For instance, wu geng 五更(five geng) means engaging in official labor in five shifts, and geng liqie更隷妾 means a female penal laborer who worked by rotation. The antonym of geng is rong 冗, which means being engaged in a specific official task at frequent but irregular intervals, outside of the rotation system. Interestingly, the Zhangjiashan bamboo strips tell us that not only short-term state laborers drawn among the common population but also lower officials (scribes 史, diviners of scapulimancy 卜, oracles 祝, etc.), and elder officials attended to their work by rotation. According to the Shuihudi 睡虎地bamboo strips, the head of a low-level department in a county (xian 縣) office of the Qin empire was called sefu 嗇夫. Under the sefu, there were subordinates, the zuo佐and shi 史. In the Shuihudi materials, we find the phrase, zuo shi rong zhe佐史冗者(zuo and shi who worked outside of the rotation system). It follows that some public servants at the zuo/shi level were on duty by rotation and worked only several months per year. On the other hand, there is no indication that officials at levels higher than sefu worked by rotation. Most sefu were paid 100 bushels (bai dan 百石) annually or more. Officials at this level were called youzhi 有秩. One salary grade below youzhi was doushi 斗食, which appears as a specific standard of annual reward in the salary scale of the Latter Han dynasty in Hou Hanshu 後漢書. However, this was originally a category of daily food supply for state laborers, and meant to receive one dou 斗 of grain each day. It is, therefore, supposed that official servants at the doushi rank were rewarded according to the number of days on duty in earlier times, but came to receive a fixed annual salary by the second half of the Former Han at the latest. By contrast, youzhi officials had already received a fixed amount of annual salary, which the word zhi 秩 originally meant, during 538 the Qin. The above facts indicate that in the era of the Shuihudi and Zhangjiashan strips, some public servants at the zou/shi level attended to their work by rotation, and were paid according to the number of days on duty. In this respect, they were not substantially different from state laborers, or punitive laborers, even though the amount of daily pay each received, and other working conditions were not the same. Yet essential differences existed between youzhi and doushi. Officials at the rank of doushi or below had characteristics between those of guan 官(public servants) and min 民(commoners). Over time, doushi became a specific rank of annual salary, included into the category of youzhi. At the same time, evidence suggesting that zou/shi officials worked by rotation disappeared from historical sources. We can thus say that the bottom of bureaucratic hierarchy fluctuated over time, and the lowest class of official servants were formed through incorporating state laborers into the sphere of bureaucrats. In this sense, there was not a deep gap between guan and min, as both sides were linked with each other in a series of gradations.