Night time. Harder than it looks.
Night isn't sunset, and it isn't decided at the airport. Here's how EASA defines it, why it's so hard to get right by hand, and how Logger works it out for you to the minute.
Logging night time looks simple: you took off in daylight, landed in the dark, so some of it was night. But how much, exactly? Most pilots can't say for sure, and that's not their fault. Here's why.
What counts as "night"?
Under EASA, night is the period between the end of evening civil twilight and the beginning of morning civil twilight. Civil twilight ends when the centre of the sun is 6° below the horizon.
Check your authority: The rule also allows another period between sunset and sunrise if the appropriate authority prescribes one.
What you actually log
You don't log the whole flight as night just because you landed after dark. Log only the minutes of flight time inside the night window. Night take-offs and landings are counted separately.
Take a flight from 18:40 to 21:10. Civil twilight ends at 19:52. That's 2:30 of flight time, but only 1:18 of it is night.
Why it's hard to do by yourself
Sunset ≠ night
Civil twilight ends after sunset. How long after depends on your latitude and the time of year. In summer at high latitudes, the gap grows a lot.
Where | Sunset to end of civil twilight |
|---|---|
Equator, any time of year | ~20 min |
London, June | ~45 min |
Tromsø, June | No night at all |
Tables, tables, tables
To do it by hand, you find the twilight table for the right place on the right date. Then you compare it with your flight times and work out the minutes that fall after twilight ends.
And you're moving, so you may need to recheck the table for a new position along the route. That's why most pilots approximate. No one really does this by hand.
Night happens where you are
Night isn't decided at the departure or the arrival airport. It's decided at the point along the route where the aircraft is at that minute, and that point keeps moving.
Take a westbound flight from 18:30 to 21:30. At departure it gets dark at 19:10. At arrival it gets dark at 20:30. Along the route, you catch up with the darkness at about 19:42.
Method | Night time |
|---|---|
Departure table | 2:20 (32 min too much) |
Arrival table | 1:00 (48 min too little) |
Along the route | 1:48 |
So which table do you use? To calculate it accurately, you'd need twilight times for the exact lat/lon you're over, at every minute of the flight.
Small details, big errors
Every day is different. Twilight times shift every day. Last week's numbers are already wrong.
Midnight crossings. Off-block on one date, on-block on the next. Whose table do you use?
The date line. Cross it and the date jumps a whole day.
Constantly on the move. Twilight tables are fixed to one position. Yours changes every minute of the flight.
One wrong assumption and the night minutes in your logbook are wrong.
How Logger does it
Enter your times. Logger does the rest.
Airports. Departure and arrival.
Date. The day of the flight.
Block times. Off-block and on-block.
Night time. Calculated automatically. Nothing to look up.
1-minute precision
Logger follows your route and checks the sun for every minute of the flight. Your night time, accurate to the minute.
Save yourself the time
Time per night flight | |
|---|---|
By hand: tables, dates, guessing the route | ~5 min |
With Logger: enter your block times | 0 min |
100 night flights a year ≈ 8 hours back. (Rough estimate.)
Logger gives you 1-minute accuracy along the whole route, automatically. It also fills in night take-offs and landings.
Night time, calculated for you.
This is the EASA perspective. Rules vary by authority and operator. Always confirm with your CAA and your operator before filling in your logbook.
