BA 2633 then U2 8123 at Gatwick
Graz → London → Lanzarote
Timetable, London time
20:00BA 2633 from Graz at the gate
13:25U2 8123 to Lanzarote leaves the gate
17 h 25 apart on the timetable, overnight
U2 8123 leaves 17 h 25 after BA 2633 arrives on the timetable: more than half a day, so not a connection we count.