UA 225 then AA 5347 at Philadelphia
Denver → Philadelphia → Richmond
Timetable, Philadelphia time
15:46UA 225 from Denver at the gate
10:02AA 5347 to Richmond leaves the gate
18 h 16 apart on the timetable, overnight
AA 5347 leaves 18 h 16 after UA 225 arrives on the timetable: more than half a day, so not a connection we count.