四分律行事鈔資持記 2.1139

2.1139

四十。《時非時經》即《阿含》別品，是以雙標。彼約脚影定一年中日夜長短，須者尋之。準俗者，此方亦以十五日為一氣，一氣有三候，一候有五日，三氣為一節（四十五日），一年有四時八節二十四氣七十二候三十六旬。《僧祇》脚影者，立日中以脚步影也。刻漏者，量水為數，隨時增減，滴漏定時，謂之刻漏。

Forty. The Shifeishi jing (Sūtra on Proper and Improper Times) is a distinct chapter of the Āgamas; hence both are indicated. It determines the length of days and nights throughout the year by foot-shadows; those who need it may consult it. As for "according to common convention", in this land fifteen days also make one solar term (qi); one term has three pentads (hou); one pentad has five days; three terms make one quarter (forty-five days); one year has four seasons, eight seasonal divisions, twenty-four solar terms, seventy-two pentads, and thirty-six ten-day periods (xun). The "foot-shadow" of the Mahāsāṃghika-vinaya means standing in the sun and measuring the shadow with footsteps. A "clepsydra" measures water for counting; it increases or decreases according to the seasons, determining the time by dripping leaks—hence it is called a water clock (clepsydra).