《明史·志·卷十三》
求昼夜加减差：以望时太阳的宫分度数为引数，代入昼夜加减数据表内，取加减分，按照比例法求取。
求昼夜加减差以望时太阳宫度为引数，入昼夜加减立成内，取加减分，依比例法求之。
To find the diurnal correction, use the solar longitude at the time of conjunction as the argument, substitute it into the table of diurnal corrections, and find the additive or subtractive minutes. Then use the method of proportion to find the correction.