UA 3578 then AV 583 at Dulles
Burlington → Washington → Santa Clara
Timetable, Washington time
16:35UA 3578 from Burlington at the gate
16:25AV 583 to Santa Clara leaves the gate
23 h 50 apart on the timetable, overnight
AV 583 leaves 23 h 50 after UA 3578 arrives on the timetable: more than half a day, so not a connection we count.