I am B777 rated pilot and software developer. Nowadays I am working on an application about flights and this app has to calculate night time. Still I am trying to figure out how to calculate night time correctly for logging purposes. As you know night definition is easy,
Night means the time between the end of evening civil twilight and the beginning of morning civil twilight, as published in the Air Almanac, converted to local time.
But calculating a flight's night time is a little bit confusing.
- Is this just related about being day or night at takeoff and landing airports?
- Or whole the route should be considered if it is day or night at that time while flying?
I searched a lot but couldn't find any formula or detailed explanation about this. Just found some sites and apps can calculate night time; but interestingly every app gives different result; and still it is unclear for me that how they calculate night time.
Example:
Departure : KMIA
Destination : LTBA
Block Off Time : 03:03Z
Block On Time : 13:36Z
Block Time : 10:33
If you calculate this flight's night time via http://www.crewlogbook.com/utilities/night_calculator.php you will get:
Night Time : 01:47
I wonder how this calculation was made?