《黄帝内经·素问·六微旨大论》
已丑之年，初之气，天时的刻数，开始于二十六刻，终止于十二刻五分；二之气，开始于十二刻六分，终止于漏水下至一百刻；三之气，开始于一刻，终止于八十七刻五分；四之气，开始于八十七刻六分，终止于七十五刻；五之气，开始于七十六刻，终止于六十二刻五分；六之气，开始于六十二刻六分，终止于五十刻。
乙丑岁，初之气，天数始于二十六刻，终于一十二刻半；二之气，始于一十二刻六分，终于水下百刻；三之气，始于一刻，终于八十七刻半；四之气，始于八十七刻六分，终于七十五刻；五之气，始于七十六刻，终于六十二刻半；六之气，始于六十二刻六分，终于五十刻。
In years with the gan branch of Yichou, the first qi, the time of day, begins at twenty-six moments, and ends at twelve moments and five minutes; the second qi, begins at twelve moments and six minutes, and ends at dripping water of one hundred moments; the third qi, begins at one moment, and ends at eighty-seven moments and five minutes; the fourth qi, starts at eighty-seven moments and six minutes, and ends at seventy-five moments; the fifth qi, starts at seventy-six moments, and ends at sixty-two moments and five minutes; the sixth qi, starts at sixty-two moments and six minutes, and ends at fifty moments.