Insomnia The Matt Barrett Cure for Jet lag and Insomnia Everyone who travels regularly to Greece has their own method of coping with the time change. Drink lots of water. Try to sleep on the flight or stay relaxed.
Some herbs are great.
Last flight I took kava-kava which made the whole thing bareable and I actually dozed for a couple hours. Valerian can work too and everyone has their favorites. Take a shower when you get to Athens. If it is morning or early afternoon take a walk and check out the city. In other words hit the ground running.