@Misd-agin, I don't think vitco was talking about flying a Cessna 152 around at 2000'.
Flying a commercial jet at FL350 above the clouds with the autopilot in. Are you flying VFR or IFR?
Well if you claim to be not using your instruments, then how are you monitoring:
your speed?
your altitude within 200'?
vertical speed?
your pitch attitude? (you can't see the horizon - you're not relying on cloud layers I hope)
your roll attitude? (ditto horizon?)
your rudder balance?
your fuel state and distribution?
your fuel temperature?
your engine parameters?
the cabin atmosphere?
the winds and TAT, SAT?
MMo?
Vls?
your heading?
Anyway, back to the OP. Just be pragmatic. If I have flown 2:24 from Malaga to Luton, and roughly the last half hour was in darkness - I log 2:00 of day flying and :24 of night flying.
If I have flown 8:37 from Tobago to Gatwick, I will typically log 1:37 of day flying and 7:00 of night flying, 'cos it got dark about an hour and a half after take off.
If you are trying to work this all out months later, the AERAD grey supplement has tables of sunrise and sunsets, so on your next longhaul flight you can go through your log book and work it out.
