Entering day vs. night flight time
ZuluLog can calculate day vs. night flight time for you, based on:
- Departure date and time
- Route of flight
- Total flight time
General information: Logging night flight time
Night flight time is calculated based on FAA regulations. Specifically, any flight time between the end of evening civil twilight and the beginning of morning civil twilight is considered night flight time.
Civil twilight is not the same as sunrise and sunset. Civil twilight is defined to begin in the morning, and to end in the evening, when the center of the Sun is geometrically 6 degrees below the horizon.
ZuluLog's internal calculations for night flight time are compatible with the official NOAA algorithm for calculating the beginning and end of civil twilight.
Note that unlike many "night time calculation" programs, ZuluLog supports multiple day/night cycles on a single flight. For example, you might take off from Sydney around sunset, fly eastward through the night, and arrive in San Francisco in the morning--this comprises one complete "night" cycle and portions of two "day" cycles.
ZuluLog also supports cases where civil twilight never ends in the summer, or never begins in the winter, if you're operating at very high or low latitudes.
And finally, ZuluLog also supports cases where your flight crosses the International Date Line.
Performing the calculations
- Log into your ZuluLog account, go to the Pilot Logbook, and click Add Flight.
- On the Flight Entry screen, fill in your departure date and time, your route of flight, and your total flight time.
- Click the "Calculate Night" button on the right-hand side of the screen.
- ZuluLog will use the information you've provided to determine how much of your flight time counts as "day" and how much counts as "night." The Day Flight Time and Night Flight Time fields will be filled in accordingly.
That's all there is to it!
Details on field entry
- Departure date and time. Depending on your account settings, you'll enter your flight date and time in:
- Local time at your departure point
- Local time at your home base
- Zulu time (UTC)
To configure which of these you'd like to use, go to Schedules -> Schedule Preferences.
- Route of flight. Enter your route of flight as usual. Keep in mind you can enter airport codes in ICAO, IATA, or FAA format. You can also enter GPS coordinates (latitude and longitude), codes for navaids, and codes for your own custom airports along your route of flight.
- Total flight time. Enter your total flight time in either the Total box (if you're in Total/Night mode) or the Day box (if you're in Day/Night mode). Make sure the Night box is empty (or contains 0).