DL 5653 then UA 800 at Boston
Columbus (Ohio) → Boston → Denver
Timetable, Boston time
19:42DL 5653 from Columbus (Ohio) at the gate
16:45UA 800 to Denver leaves the gate
21 h 03 apart on the timetable, overnight
UA 800 leaves 21 h 03 after DL 5653 arrives on the timetable: more than half a day, so not a connection we count.