DL 5619 then B6 1620 at Boston
Milwaukee → Boston → London
Timetable, Boston time
22:02DL 5619 from Milwaukee at the gate
19:10B6 1620 to London leaves the gate
21 h 08 apart on the timetable, overnight
B6 1620 leaves 21 h 08 after DL 5619 arrives on the timetable: more than half a day, so not a connection we count.