Originally Posted by
BillyDWilliazs1
Personally, I would go to Rhodes or Crete. Both are open sans tourists in Feb. If in Crete, I'd go to Rethymno and Chania, and if there's time, the Samaria Gorge and Knossos.
In Rhodes, there would be plenty to see in Old Town, and perhaps an excursion to Lindos.
Several things to remember here. Firstly the OP wants to do a day trip from Athens, so there has to be a morning flight from Athens to the island and an evening flight back from whichever island he visits. That cuts out some of the islands on the winter timetable, but does leave Rhodes and Chania or Heraklion on Crete amongst others including Kos, Lesbos, Samos, Chios, Santorini and on some days of the week Mykonos and Corfu.
Secondly, on Crete, there's only time to do one of the four suggestions and get back to the airport to catch the Athens flight the same day. The Samaria Gorge is out anyway as it is closed to visitors in the winter due to the high incidence of flooding and rockfalls.
Personally I'd go for Rhodes as if it does pour down there are museums and galleries to visit, and if it is dry the Old City without tourists is spectacular.
Santorini has great views if it is dry, but nothing to do if it isn't. February is in the rainy season in Greece, and the days are still short as well.