AA 353 then AA 257 at Miami
Boston → Miami → Mexico City
Timetable, Miami time
18:43AA 353 from Boston at the gate
18:30AA 257 to Mexico City leaves the gate
23 h 47 apart on the timetable, overnight
AA 257 leaves 23 h 47 after AA 353 arrives on the timetable: more than half a day, so not a connection we count.