UA 3903 then AA 2111 at San Francisco
Seoul → San Francisco → Dallas-Fort Worth
Timetable, San Francisco time
08:46UA 3903 from Seoul at the gate
00:11AA 2111 to Dallas-Fort Worth leaves the gatealso QF 4479, GF 6675
15 h 25 apart on the timetable, overnight
AA 2111 leaves 15 h 25 after UA 3903 arrives on the timetable: more than half a day, so not a connection we count.