瑜伽師地論略纂 8.22

8.22

論「謂夜四分中過初一分，是夜初分」等者，彼土世俗晝夜各立四分，佛法晝夜各立三時，以三時攝四分：從初向後，過初一分，名初時；從後向前，過後一分，名後時；中間二半分，名夜中時。其晝亦爾。此中順世俗。

Where the treatise says, "Passing the first watch of the four watches of the night is the early watch of the night," and so forth: In worldly custom in that land, day and night are each divided into four watches, whereas the Buddha-Dharma divides day and night each into three periods, subsuming the four watches into three periods: from beginning to end, passing the first watch is called the first period; from end to beginning, passing the final watch is called the final period; the middle two-and-a-half watches are called the middle period of the night. The day is also like this. Here it accords with worldly custom.