《明史·志·卷三十六》
凡是王公大臣报丧奏闻，太史监选择皇帝亲临丧礼的日期。
凡王公大臣讣奏，太史监择皇帝临丧日期。
Whenever the death of a prince or minister was reported to the emperor, the Grand Astrologer would choose the date for the emperor to attend the funeral.