I'll be taking my first true polar route flight from DTW to HKG on DL mid-December. It leaves the gate at 340p and arrives HKG at 845p. Given that it's near the winter solstice, will there be daylight in the second half of the flight or will it remain dark after the sun sets a quarter into the flight?

I checked a day/night map but couldn't figure out the potential paths of the second half of the flight. So I still can't doubt that the plane could leave the dark region for a few hours before the sun sets again. However, I know that the sun definitely sets a few hours after take off.

I did the math, and I'll be able get a full night's rest on the flight. That's a first for a trans-Pacific flight, after having flown USA-NRT flights that departed around noon - leaving me nodding off in NRT waiting for my connecting flight.

- Pat