《宋书·志·卷十三》
求合朔、月食：取朔、望夜半在阴阳历中相应日期和曰余，曰余尾数有半的将半去掉，改用小分三百零三，将其加上差数，小分满六百零六则减去六百零六并在曰余上进一，日余满通法的则减去通法且在曰数上进一，曰数满阴阳历长则减去阴阳历长，将其与阴阳历中的日期对应并外推一天就是朔、望时刻在阴阳历中的日期。
求合朔月食：置朔望夜半入阴阳历日及余，有半者去之，置小分三百三，以差数加之，小分满六百六从日余，日余满通法从日，日满一历去之。命日算外，则朔望加时入历也。
To calculate the conjunction of the moon and a solar eclipse: Take the half night of the new moon and full moon and the corresponding dates and remaining days in the Chinese and Western calendars; if the remaining days have a half remainder, remove the half and use the small fraction three hundred and three; add the difference to them; when the small fraction is full six hundred and six, subtract six hundred and six and add one to the remaining days; when the remaining days reach the general rule, subtract the general rule and add one to the number of days; when the number of days reaches the length of the Chinese and Western calendars, subtract the length of the Chinese and Western calendars; correspond them with the dates in the Chinese and Western calendars and extrapolate one day, which is the date of the new moon and full moon in the Chinese and Western calendars.