LX 317 then FB 492 at Zurich
London Heathrow → Zurich → Sofia
Timetable, Zurich time
11:55LX 317 from London Heathrow at the gate
10:00FB 492 to Sofia leaves the gate
22 h 05 apart on the timetable, overnight
FB 492 leaves 22 h 05 after LX 317 arrives on the timetable: more than half a day, so not a connection we count.