1-Is it permissible for someone who intentionally broke their fast in Ramadan to fast the following day?

Whoever intentionally breaks their fast during Ramadan without a valid excuse has committed a grave sin. They must repent to Allah, continue fasting for the remainder of Ramadan, and make up for the day they broke their fast. If the fast was broken by sexual intercourse, then in addition to making up for the day, they must also perform the major expiation (kaffarah kubra): freeing a believing slave. If they cannot find one, then they must fast for two consecutive months. If they are unable to do that, then they must feed sixty needy people.