DL 5641 then B6 1620 at Boston
Cleveland → Boston → London
Timetable, Boston time
20:00DL 5641 from Cleveland at the gate
19:10B6 1620 to London leaves the gate
23 h 10 apart on the timetable, overnight
B6 1620 leaves 23 h 10 after DL 5641 arrives on the timetable: more than half a day, so not a connection we count.