UA 1550 then DL 670 at San Francisco
Detroit → San Francisco → New York JFK
Timetable, San Francisco time
10:46UA 1550 from Detroit at the gatealso NZ 2888
23:05DL 670 to New York JFK leaves the gatealso AM 4305, VS 4848, LA 6189, KQ 7055
12 h 19 apart on the timetable
DL 670 leaves 12 h 19 after UA 1550 arrives on the timetable: more than half a day, so not a connection we count.