AA 5218 then AA 1232 at Philadelphia
Nashville → Philadelphia → Boston
Timetable, Philadelphia time
19:29AA 5218 from Nashville at the gate
19:28AA 1232 to Boston leaves the gate
23 h 59 apart on the timetable, overnight
AA 1232 leaves 23 h 59 after AA 5218 arrives on the timetable: more than half a day, so not a connection we count.