What is the ruling on delaying the fasting of three specific days that were vowed upon the occurrence of a certain event, if Ramadan begins before they are fasted?

If a person swears to fast for three days upon doing a certain thing and then does it, they have the option between fulfilling the fast or offering expiation for the oath (kaffarat al-yameen). It is not permissible to fast the days they swore to during Ramadan, because Ramadan is dedicated solely to the Ramadan fast. If immediate fasting is impossible due to Ramadan, then the swearer is considered to have broken their oath and is obliged to offer expiation. The expiation for an oath is feeding ten poor persons, or clothing them, or freeing a slave; whoever cannot afford that must fast for three days.