BA 393 then VS 155 at Heathrow
Brussels → London → Las Vegas
Timetable, London time
17:45BA 393 from Brussels at the gate
17:40VS 155 to Las Vegas leaves the gate
23 h 55 apart on the timetable, overnight
VS 155 leaves 23 h 55 after BA 393 arrives on the timetable: more than half a day, so not a connection we count.