月令是我国古代一种重要的岁时文献，按内容特点可以分为综合性月令与农业月令。自东汉《四民月令》起，综合性月令《唐月令》、农业月令《四时纂要》《养余月令》《农圃便览》等一系列月令文献吸纳了二十四节气系统，并将之作为每月重要的时间节点。二十四节气在与月令文献的结合中起到安排祭祀仪式、预测气象丰歉、指导农事生产等作用，具有实用化与经验化的特点。二十四节气在历代月令文献中呈现出由关注庄园农事，转向服务祭祀占候，又转向回注重农业生产生活技术的衍变趋势。

The moonthly ordinances (Yueling) is an important style of chronography documents in ancient China. which can be divided into comprehensive moonthly ordinances and agricultural moonthly ordinances according 1o its content. Since Simin Yueling of the Eastern Han Dynastys, a series of comprehensive monthly ordinances, such as Tang Yueling and the agricultural monthly ordinances, such as Sishi Zuanyao, Yangyu Yueling and Nong pu Bianlan, have incorporated the system of the 24 Solar Terms and taken them as important monthly points. The combination of the 24 Solar Terms with the moonthly ordinances played a practical and empirical role in arranging rituals, predicting westher and harvest, and guiding agricultural production. The 24 Solar Terms have shown a tendeney to change from focusing on farming to serving rituals and divination, and then to focusing on agricultural production and life techniques.