四分律刪繁補闕行事鈔 1.486

1.486

今約閏月結之，進不三例：若閏五月六月，定百二十日住。若閏四月者，從四月十六日至閏月一日結者，並四月住；若閏月二日已後結者，漸漸轉少，以越閏月過，取五月一日，實夏成正結故；若五月一日後結者，皆三月住，以數滿九十日故。三若閏七月者，從四月十六日後，五月一日結者，盡三月住，由未至閏故；五月二日已後結者，皆四月住，由九十日未滿，入閏月不成數故。餘如《疏鈔》。

Now, determining the binding with respect to the intercalary month, advancing or not presents three cases: If the intercalary month falls in the fifth or sixth month, one definitely dwells for one hundred and twenty days. If there is an intercalary fourth month: from the sixteenth day of the fourth month up to the first day of the intercalary month, those who bind all dwell for four months; if bound on or after the second day of the intercalary month, it progressively decreases, because bypassing the intercalary month and taking the first day of the fifth month constitutes the genuine summer and true binding; if bound after the first day of the fifth month, all dwell for three months, because the count of ninety days is completed. Third, if there is an intercalary seventh month: from after the sixteenth day of the fourth month, those who bind on the first day of the fifth month dwell for the full three months, because the intercalary month has not yet arrived; those who bind on or after the second day of the fifth month all dwell for four months, because the ninety days are not yet complete, and entering the intercalary month does not count toward the number. The rest is as in the Commentary.