BA 669 then DL 9931 at Heathrow
Marrakesh → London → Atlanta
Timetable, London time
20:20BA 669 from Marrakesh at the gate
16:35DL 9931 to Atlanta leaves the gate
20 h 15 apart on the timetable, overnight
DL 9931 leaves 20 h 15 after BA 669 arrives on the timetable: more than half a day, so not a connection we count.