BA 891 then BA 892 at Heathrow
Tbilisi → London → Sofia
Timetable, London time
11:50BA 891 from Tbilisi at the gate
11:10BA 892 to Sofia leaves the gate
23 h 20 apart on the timetable, overnight
BA 892 leaves 23 h 20 after BA 891 arrives on the timetable: more than half a day, so not a connection we count.