Upvote:1
Assuming it is the air-borne time, then, it could be because of the jet stream, plus Corfu to Athens is West to East.
Upvote:3
The question is really not specific enough for us to answer with any precision. There are many factors that can affect the duration of a flight, and we don't even know exactly which parts of the flight are included in the timings you cite. I will assume that they are from your departure gate to your arrival gate.
The most likely explanation seems to be that when you leave Athens your plane is generally waiting behind a line of several other planes before it can take off, and when flying to Athens this does not happen. Another possible factor is that one of the runways at Athens is much closer to the terminal than the other. If your outbound flight used the farther runway, and your inbound flight did not, that would contribute to the difference in time.