BA 689 then BA 836 at Heathrow
Santorini → London → Dublin
Timetable, London time
15:30BA 689 from Santorini at the gate
17:20BA 836 to Dublin leaves the gate
1 h 50 apart on the timetable
The last days
BA 689 and BA 836 weren’t both flown 15 min to 12 h apart in the last 21 days.
Statistics from past flights, not live flight information. Always check times and your connection with your airline, and don’t base travel or booking decisions on these numbers.