Just my story. I went to Japan for a 3 week vacation. In Finland I had the return flight time set in my N900 calendar. As the time went by and was the time to go home, I checked my calendar and thought "oh, the flight is 16.30 in the evening". Don't have to get up early.

You can all guess what happened.

Yeah, I maybe should have used my brain a little more and read the actual travel documents once more. But I really didn't see that coming. I just automatically assumed that my calendar events would be as I have entered.

Once solution would probably be an explicit Time Zone button in the +Add Event dialog. Then the user would at least think about time zones when entering. As an infrequent traveler it didn't even enter my mind.