TP 4399 then AV 2354 at San Francisco
Boston → San Francisco → Denver
Timetable, San Francisco time
00:25TP 4399 from Boston at the gate
16:24AV 2354 to Denver leaves the gate
15 h 59 apart on the timetable
AV 2354 leaves 15 h 59 after TP 4399 arrives on the timetable: more than half a day, so not a connection we count.