SL 394 then UA 838 at Narita
Bangkok Don Mueang → Tokyo → San Francisco
Timetable, Tokyo time
17:15SL 394 from Bangkok Don Mueang at the gate
16:55UA 838 to San Francisco leaves the gate
23 h 40 apart on the timetable, overnight
UA 838 leaves 23 h 40 after SL 394 arrives on the timetable: more than half a day, so not a connection we count.