U2 8446 then BY 356 at Gatwick
Nantes → London → Agadir
Timetable, London time
11:40U2 8446 from Nantes at the gate
08:50BY 356 to Agadir leaves the gate
21 h 10 apart on the timetable, overnight
BY 356 leaves 21 h 10 after U2 8446 arrives on the timetable: more than half a day, so not a connection we count.