DL 1500 then BA 226 at Atlanta
Cleveland → Atlanta → London
Timetable, Atlanta time
10:00DL 1500 from Cleveland at the gate
22:15BA 226 to London leaves the gate
12 h 15 apart on the timetable
BA 226 leaves 12 h 15 after DL 1500 arrives on the timetable: more than half a day, so not a connection we count.