Night Time Calculator
Find when night starts and ends at an airport on any date, or count the night hours of a flight from its takeoff and landing times in UTC. The result shows the 14 CFR 1.1 night next to the 61.57(b) period.
Free · runs in your browser · nothing is uploaded
The night time calculator finds when night starts and ends at a place on a given date, and how much of a flight falls in darkness. Night under 14 CFR 1.1 runs from the end of evening civil twilight to the beginning of morning civil twilight, so the sun-times mode shows that window directly.
The flight mode counts the night time of one flight from departure and arrival airports and UTC takeoff and landing times. It follows a straight great-circle path at constant speed and counts a minute as night when the Sun’s centre is more than 6 degrees below the horizon. The Air Almanac is the legal source in 14 CFR 1.1. This tool is an astronomical calculation, not an official determination.
How to use the night time calculator
Sun times and night window
- Choose an airport, or enter the latitude and longitude of the place.
- Enter the date. The night that begins that evening is shown.
- Pick the UTC offset of the airport clock, for example UTC-04:00 for New York in June. UTC is always shown.
- Read the morning civil twilight start, sunrise, sunset and evening civil twilight end, in UTC and at your offset.
- Read the 14 CFR 1.1 night that begins that evening and the 61.57(b) period, each with its length. Near the poles the tool explains the case instead of giving a time.
Night time of a flight
- Enter the departure airport and the arrival airport.
- Enter the takeoff date and time in UTC, then the landing date and time in UTC. The flight can be up to 48 hours long.
- Read the night time as h:mm and as decimal hours in hundredths and tenths.
- Check the total time, the Sun’s altitude at takeoff and landing, and the day and night parts.
In the flight mode the departure and arrival airports are picked from the same list as in the sun-times mode. Type at least two letters of the ICAO or IATA code, or part of the name, and choose a line from the list. Dates and times are always UTC, so convert a local time first with the Zulu time converter.
How do I calculate night flight time for my logbook?
Run the flight mode with the takeoff and landing times in UTC. It counts each minute the Sun is more than 6 degrees below the horizon at the aircraft’s position and returns the night time in hours. Write that figure in your logbook’s night column.
Example: a flight from JFK to London Heathrow (EGLL) leaving 25 October 2026 at 23:00 UTC and landing 26 October at 07:00 UTC has night from 23:00 to 06:30. Night time is 7:30, or 7.50 hours. The Sun is at -11.9 degrees at takeoff and +1.4 degrees at landing.
When does night start for a pilot?
For logging under 14 CFR 1.1, night starts at the end of evening civil twilight and ends at the beginning of morning civil twilight. For passenger-carrying night currency under 14 CFR 61.57(b), the period starts one hour after sunset and ends one hour before sunrise. The two windows differ, so check which rule applies.
| Rule, JFK 21 June 2026 (UTC-4) | Start | End | Length |
|---|---|---|---|
| 14 CFR 1.1 night | 21:03 | 04:51 next day | 7:48 (468 min) |
| 14 CFR 61.57(b) period | 21:30 | 04:25 next day | 6:55 (415 min) |
What is civil twilight?
Civil twilight is the period between sunrise or sunset and the moment the Sun’s centre is 6 degrees below the horizon. In the morning it runs from that 6 degree point to sunrise. In the evening it runs from sunset to that point. Sunrise and sunset are a little higher, at 50 arcminutes below the horizon, which allows for the Sun’s radius and refraction.
How accurate is the night time calculator?
Against the U.S. Naval Observatory table, all 58 sunrise, sunset and civil twilight times we checked were within 1 minute. The largest gap was 0.5 minute, and the USNO rounds to the whole minute. The check covered 9 airports, 17 place and date pairs in 2026, from 37 degrees south to 69.7 degrees north.
The Sun’s position comes from astronomy-engine, with refraction turned off. This check compares against the USNO table, not the Air Almanac itself.
What happens near the poles?
Near the poles the Sun can stay above or below the twilight limits for a day or longer. When civil twilight never ends, there is no 14 CFR 1.1 night that evening, and the tool says so.
- Tromso (69.68 N) on 21 December: there is no sunrise. Civil twilight runs from 08:32 to 12:53 UTC, and the night beginning that evening is about 19 h 40 min.
- Anchorage, 20 to 21 June: civil twilight never ends, so there is no 1.1 night. Sunset is at 07:42 UTC and sunrise at 12:21 UTC, a 279 minute gap, which gives a 61.57(b) period of 159 minutes.
What does the flight mode assume?
The flight mode follows a straight great-circle line at constant speed, checked in one-minute steps. It does not model the real route, climb, holding, altitude or terrain. A minute counts as night when the Sun’s centre is more than 6 degrees below the horizon at the aircraft’s position.
An aircraft that stays at JFK from 00:33 to 01:33 UTC on 21 June has 30 minutes of night, because civil twilight ends at 01:03 UTC.
Sources
- 14 CFR 1.1, definition of night, eCFR text as of 2026-10-20, read 2026-10-25.
- 14 CFR 61.57(b), night currency for carrying passengers, eCFR text as of 2026-10-20, read 2026-10-25.
- U.S. Naval Observatory rise, set and twilight definitions, read 2026-10-25.
- USNO sunrise, sunset and twilight table, fetched 2026-10-25 (accuracy check).
- astronomy-engine 2.1.19 (MIT licence), Sun position.
Questions from readers
Does this calculator give the official night?
No. The Air Almanac is the legal source for night under 14 CFR 1.1. This tool is an astronomical calculation and makes no official determination.
Why do the two night periods differ?
They follow different rules. The 14 CFR 1.1 night runs from the end of evening civil twilight to the start of morning civil twilight. The 14 CFR 61.57(b) period runs from one hour after sunset to one hour before sunrise.
What times do I enter for a flight?
Enter the takeoff and landing date and time in UTC. A flight can be up to 48 hours long.
Why is there no 1.1 night at some high-latitude airports?
When civil twilight never ends, there is no 14 CFR 1.1 night that evening. Where the Sun still sets and rises, the 61.57(b) period can still be shown.
How do I enter the result in my logbook?
Write the night time in the night column in the unit your logbook uses, for example 7:30 or 7.5 hours. The calculator shows both. Your authority, school or employer decides which rounding it accepts.
Does the flight mode follow my actual route?
No. It assumes a straight great-circle path at constant speed and ignores climb, holding, altitude and terrain. Treat the figure as an estimate for that simple flight.
How does the FAA define night?
For logging, the FAA definition sits in 14 CFR 1.1: night runs from the end of evening civil twilight until morning civil twilight begins, using Air Almanac times in local time. The tool calculates civil twilight with the sun’s centre 6 degrees below the horizon, but the Air Almanac is the legal source.
Is FAA night currency the same as night time for logging?
No. The general night definition in 14 CFR 1.1 is not the same as night passenger-carrying currency. Under 61.57(b), that currency starts 1 hour after sunset and ends 1 hour before sunrise, a narrower window. The tool shows both windows, so you can compare them for the same flight.
Related tools
- Pilot currency checker: use it to check the 61.57 night rule for carrying passengers.
- Pilot logbook template: use it to print pages with a night column.
- Electronic pilot logbook: use it to keep night time with the rest of your flight records.
- Flight time calculator: use it for the flight duration between two airports.
- Zulu time converter: use it to convert date and times to and from UTC.
- Logbook tools: use it to see every logbook tool in one place.
- Home: use it to browse the other tools on this site.