Is it obligatory for someone who deliberately broke their fast during an expiatory fast for an oath to refrain from eating for the remainder of the day?

Whoever intends to break their fast while fasting has broken it, and it is not permissible to intentionally break a fast that is obligatory. Whoever intentionally breaks a fast for an expiation oath (kaffarat al-yamin) must fast another day. They are not required to abstain from eating for the rest of the day they broke their fast, because abstention for someone who broke their fast without a valid excuse is specific to the days of Ramadan due to their sanctity. Al-Nawawi said: "Abstention, resembling the fasting persons, is a characteristic of Ramadan... So there is no abstention for one who intentionally broke their fast in a vow, or a compensatory fast (qada'), or an expiation." Thus, abstention is specific to designated fasts like Ramadan and designated vows, and does not include the fast for an expiation oath.