AA 3294 then UA 2400 at Boston
Charlotte → Boston → San Francisco
Timetable, Boston time
19:10AA 3294 from Charlotte at the gate
18:01UA 2400 to San Francisco leaves the gate
22 h 51 apart on the timetable, overnight
UA 2400 leaves 22 h 51 after AA 3294 arrives on the timetable: more than half a day, so not a connection we count.