This study aims to prove that the demands of the times and the interests of the rulers in the books related to Monthly Ordinances existed continuously throughout the Han Dynasty (Former Han and Later Han), and also seeks to discover what kinds of needs of those times were reflected in the content of the books.
The general belief is that, when Lushichunqiu(呂氏春秋) 'Shieryueji(十二月紀)' were compiled, the "Monthly Ordinances" had become complete, and from then on the ordinances began to settle. However, the analysis of four kinds of books related to Monthly Ordinances brought the conclusion that the monthly ordinances did not come after the 'Shieryueji', but as the necessity of rules relying on monthly ordinances had consistently come up, the books such as Liji(禮記) 'Yueling(月令)', Lushichunqiu 'Shieryueji' were compiled all about the same time at the end of the Former Han Dynasty.
As the ancient Chinese society was based on agriculture, there often appeared timely agricultural guidelines in the books about emperors' rulings. But the guidelines mostly corresponded to general customs. Then when the Five Elements theory was becoming popular, there are records of governing rules controlled by those elements in the books related to Monthly Ordinances. However, until the beginning of the Han Dynasty, the Monthly Ordinances were not regarded as something that had to be followed as the norms of an emperor. But the changes show during the reign of Emperor Xuan(宣帝) of the Former Han Dynasty. Weixiang(魏相), who was one of the ministers at the time, insisted that the emperor had to follow the Four Seasons. As a result, relief measures for. the poor during drought seasons and awarding good deeds of officials were all carried out in March according to the guidelines of Monthly Ordinances. Subsequently, by the time of the Emperor Yuan(元帝) and Emperor Cheng(成帝), "Following the Four Seasons" became the role of an emperor. This trend of thinking continued in Later Han and by the time of Emperor Zhang(章帝) and Emperor An(安帝), the virtues of looking after the elderly and helping the poor, quoted in the 'Yueling', were practiced.
Meanwhile, when we look at Houhanshu(後漢書) 'Liyizhi(禮儀志)', there is a clearly different point from the previous books related to Monthly Ordinances; We cannot find a farming calendar any more in those books, but only the systems for the emperors and officials in charge are emphasized, concentrating mostly on rites. This resulted from the expansion of autonomy in local governments. By that time, the central government could not control the whole vast area of the country with unified ruling guidelines, and it is believed that the central government hoped to secure power through rites and ceremonies. Then the local governors must have felt strongly the needs of regional Monthly Ordinances, and this was expressed in the Simiyueling(四民月令), a guideline for rulings based on Monthly Ordinances, specially written for regional governors.