《宋书·志·卷十二》
曰余满法则减去曰法并在数上加一，数满二十七则减去二十七并在余上减去周曰余，如余不够减，则在敷上减一。在余上加上周虚即可。
日余满日法成日，日满二十七去之。又除余如周日余，日余不足者，减一日，加周虚。
If the solar remainder is full, subtract the solar law and add one to the number. If the number is full 27, subtract 27 and subtract the Zhou solar remainder from the remainder. If the remainder is not enough to subtract, subtract one from the cover. Add the Zhou void to the remainder.