瑜伽論記 4.387

4.387

日夜等者，如俱舍云：百二十剎那為怛剎那量，臘縛此六十，此三十須臾，此三十晝夜，三十晝夜月，十二月為年，牟呼栗多此云須臾故也。

Regarding 'days, nights, etc.': as the Kośa states: One hundred and twenty kṣaṇas make the measure of a tat-kṣaṇa; sixty of these make a lava; thirty of these make a muhūrta; thirty of these make a day and night; thirty days and nights make a month; twelve months make a year. 'Muhūrta' is translated here as 'xuyu'.