VS 12 then BA 414 at Heathrow
Boston → London → Tenerife South
Timetable, London time
09:55VS 12 from Boston at the gate
09:50BA 414 to Tenerife South leaves the gate
23 h 55 apart on the timetable, overnight
BA 414 leaves 23 h 55 after VS 12 arrives on the timetable: more than half a day, so not a connection we count.