VA 8311 then UA 597 at San Francisco
Boston → San Francisco → Bozeman
Timetable, San Francisco time
12:09VA 8311 from Boston at the gate
12:00UA 597 to Bozeman leaves the gate
23 h 51 apart on the timetable, overnight
UA 597 leaves 23 h 51 after VA 8311 arrives on the timetable: more than half a day, so not a connection we count.