2,833. Annulling Vows All Day Long

Hilchos Nedarim 12:14

A father or a husband who is not mentally sound can annul a vow. A minor can’t effect marriage, so he can’t annul a vow. A man can annul the vows of two wives or of two daughters simultaneously.

Hilchos Nedarim 12:15

Vows can be annulled all day long, as follows: If a woman made a vow at the start of Sunday night (which is Monday in halacha), the vow can be annulled that whole night and the whole day on Monday. If she made a vow at the end of the day, right before nightfall and he annulled it before nightfall, it’s annulled. If he didn’t annul it by nightfall, he may no longer do so.