i think he might be talking about the direction of flight and/or the way in which flight direction and the spin of the earth ( time zones) interact.

I Read all the links about and looked for some of my own. The first one is time zones in 2004. ( ha ha I'm good ) so we know what we are talking about. we have to see a map and its time zones to accurately look at this issue. I dont know which way the airport runway points... but the second link shows the flight path... well the PLANNED path according to that and the ime zone map they might have crossed and then recrossed the international dateline. I dont knnow what reprecussions that has.

World Time Zone Map
Image:Oceanic 815 Planned Route.png - Lostpedia
Oceanic Flight 815 - Lostpedia