A blissful reward that's meant to be a punishment. Possibly the most stupid punishment a school can impose. It is a period of time when an offending kid is not allowed to return to their for seriously breaking rules. Most kids get excluded because school is the last place on Earth they want to be. So they get what they want in the end.
Cassie was given an 8-day exclusion for bunking off, so she smiled, relaxed, and enjoyed the freedom.