《宋书·志·卷十二》
将合余减合终合数，可减一次的星合在前一年发生，可减两次的则在前两年，不够减的就在当年发生。
以合终合数减合余，得一者星合往年，得二者合前往年，无所得，合其年。
Deduct the conjunction remainder by the final conjunction number, if it can be deducted once, the conjunction of stars happens in the previous year, if it can be deducted twice, it happens in the previous two years, if it cannot be deducted, the conjunction happens in the same year.