Flight number or route doesn't matter all that much.

First off, you weren't really flying west to east. It looks that way on a 2-dimensional map, but you are really flying mostly north then mostly south.

Also, if you happen to be sitting on the north pole, you will see the sun shining from March 21 until Spetember 21, 24 hours a day (assuming no clouds of course). As the calendar approaches the summer soltice on June 21, the area where the sun shines 24 hours/day gets closer and closer to the Arctic Circle. So, at this time of year, it doesn't really matter which side of the pole you're on, it's going to be sunny all the time. (And at the north pole, the sun sets in the south and rises in the south.)