Hi.
I've written a logbook application (web based) and am looking at the whole night flight thing.
At the moment I'm getting the sunset and sunrise at the departure and destination and averaging them, to give a single SR / SS for the flight. I'm then working out the night time based on departure time and arrival time of the aircraft. If anyone knows the exact 'formula' to work out the proper values (and I can guarantee it's going to need a LOT of maths), I'd love to hear it.
Anyone interested -
http://www.henrybevan.co.uk/logbook
NW3