B6 15 then AV 2354 at San Francisco
New York JFK → San Francisco → Denver
Timetable, San Francisco time
11:08B6 15 from New York JFK at the gatealso TP 4397
05:00AV 2354 to Denver leaves the gate
17 h 52 apart on the timetable, overnight
AV 2354 leaves 17 h 52 after B6 15 arrives on the timetable: more than half a day, so not a connection we count.