BA 212 then BA 872 at Heathrow
Boston → London → Krakow
Timetable, London time
06:25BA 212 from Boston at the gate
06:05BA 872 to Krakow leaves the gate
23 h 40 apart on the timetable, overnight
BA 872 leaves 23 h 40 after BA 212 arrives on the timetable: more than half a day, so not a connection we count.