Flight London Gatwick Airport departs from London London Gatwick Airport at 20:15 and arrives at Krakow John Paul II International Airport at 23:45.
The flighttime is about 2h 30m. The distance travelled ("as the bird flies"): 2224 Km. So the average speed is roughly 890 Km.
There is an 1 hour time difference between London and Krakow