DL 1388 then UA 4500 at Detroit
Raleigh-Durham → Detroit → Washington
Timetable, Detroit time
07:33DL 1388 from Raleigh-Durham at the gate
19:45UA 4500 to Washington leaves the gate
12 h 12 apart on the timetable
UA 4500 leaves 12 h 12 after DL 1388 arrives on the timetable: more than half a day, so not a connection we count.