本文討論古代中國關於白天與黑夜時間分配的觀念問題，通過這樣一個看似平常的歷史現象，來結合古代法律、社會生活和思想觀念的各種文獻資料，討論一個思想史問題，即為什麼古代中國對於人們在白天與黑夜的不同活動，會普遍持有「合法」與「非法」、「正常」與「非常」的倫理道德觀念，特別是為什麼古代官方對於「夜景曉散」，總是會抱有「傳習妖教」或者「圖謀不軌」這樣嚴厲的批評與高度的警惕。同時，本文也指出，古代這種建立在傳統農村生活基礎上的時間分配觀念，宋元以後，在城市生活和商業活動的影響下漸漸崩壞，在這種秩序的變化中，呈現了古代生活向現代生活轉化的一個側面。

This paper discusses the conception of time regarding how to allot day and night in ancient China, and studies the textual material of ancient law, social life, and conception carefully. I will talk about a problem of intellectual history: why the ancient Chinese people would generally think of the “legality” or “illegality”, “normaicy” or “abnormaicy” about actions that take place at day or night, and especially why the ancient government would take “assembling at night and separating at day” as “spreading heathendom” or “hatching a sinister plot”. Moreover, the government would criticize it strictly and be highly watchful of such phenomena it. At the same time, this paper points out that the conception of alloting time, which was based on the traditional rural customs, collapsed gradually because of the rise of city life and commercial activity from the Song and Yuan dynasty. In this period of changing order, we can see one side of the transformation from ancient life to modern life.