UA 3909 then UA 1147 at San Francisco
Chicago O'Hare → San Francisco → Chicago O'Hare
Timetable, San Francisco time
22:20UA 3909 from Chicago O'Hare at the gate
15:20UA 1147 to Chicago O'Hare leaves the gatealso AC 4185, CA 7326, VA 8104, NZ 9313
17 h apart on the timetable, overnight
UA 1147 leaves 17 h after UA 3909 arrives on the timetable: more than half a day, so not a connection we count.