UA 938 then BA 438 at Heathrow
Chicago → London → Amsterdam
Timetable, London time
12:00UA 938 from Chicago at the gate
11:50BA 438 to Amsterdam leaves the gate
23 h 50 apart on the timetable, overnight
BA 438 leaves 23 h 50 after UA 938 arrives on the timetable: more than half a day, so not a connection we count.