U2 8123 then U2 7681 at Lisbon
London Gatwick → Lisbon → Barcelona
Timetable, Lisbon time
17:00U2 8123 from London Gatwick at the gate
18:30U2 7681 to Barcelona leaves the gate
1 h 30 apart on the timetable
The last days
U2 8123 and U2 7681 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.