Night Flight Time Calculator for EASA & FAA logbooks

Flight Date

Enter date as two-digit day, two-digit month, four-digit year
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Departure

Arrival

Leave blank for logbook use — EASA and FAA define night at surface level, not at altitude.

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Airport Solar Data

🛫 DEP
--
Dawn (-6°) --:--
Sunrise --:--
Sunset --:--
Dusk (-6°) --:--
61.57(b) --:--
🛬 ARR
--
Dawn (-6°) --:--
Sunrise --:--
Sunset --:--
Dusk (-6°) --:--
61.57(b) --:--

Flight Timeline

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Night (-6°)
Twilight
Day

Solar Intercept Map

Twilight shade (−0.83° to −6°)
Night shade (below −6°)
Shading is the sky at one instant (the crossing time); markers are where your route crossed each threshold.Why aren't the markers exactly on the shading edge?Picture night as a giant shadow that sweeps slowly across the Earth as it spins — like a curtain being drawn closed.

The shaded area is a single photo of that curtain, frozen at one instant. But your aircraft crossed each line (−0.83° and −6°) at slightly different times, and the curtain kept moving in between. So a marker for a line crossed a little earlier or later can sit just beside the frozen edge, not exactly on it.

Nothing is wrong: your crossing times and the night total stay accurate. A single snapshot simply can't hold two moments at once.

How was this calculated?

Estimate NightLog Pro models your flight as a constant-speed great-circle path and checks the sun's position each minute. Real routing, winds and climb/descent shift the actual crossings by a few minutes. Your official logbook remains the record of authority.

Flight Manifest

Awaiting Calculation Enter flight details and calculate to view manifest.
Help & Documentation
NightLog Pro gives a close estimate, not a certified figure. Here is exactly why.
  • What we compute: the exact moments the sun crosses -6° (civil twilight) and -0.83° (sunset/sunrise) at positions sampled once per minute, using the SunCalc astronomical model.
  • What we assume: a constant ground speed along the great-circle (shortest) track, no wind, and a surface-level horizon unless you enter a Flight Level.
  • Why it can't be exact: your real flight has climb, descent, ATC routing, holding and wind, so your true track and timing differ from the model. Sunrise/sunset times themselves also vary with refraction and terrain.
  • How close: for normal routings the threshold crossings are typically within a few minutes; deviations grow on heavily re-routed or high-latitude flights.
⚠️ Use NightLog Pro to estimate and cross-check. Your official logbook and your operator's procedures remain the record of authority.
Step 1: Enter your flight date in DD-MM-YYYY format
Step 2: Select departure airport and enter Off-Blocks time (UTC)
Step 3: Select arrival airport and enter On-Blocks time (UTC)
Step 4: Press "Calculate Night Time"

💡 Tip: All times must be in UTC. The app handles midnight crossings automatically.
NightLog Pro uses Great Circle interpolation to calculate your great-circle flight path, sampling your position every 1 minute along the route.
  • SunCalc Library: Established astronomical model for sun position
  • -6° Threshold: Civil twilight (EASA Part-FCL & FAA 14 CFR 1.1 night)
  • -0.83° Threshold: Sunset/sunrise (FAA 14 CFR 91.209 position lights)
  • Great-circle path: Constant-speed shortest-path approximation between the two airports
Official sources
What is "Night" according to EASA Part-FCL?
Night is defined as the period between the end of evening civil twilight and the beginning of morning civil twilight.

What is "Night" according to the FAA?
14 CFR 1.1 defines night using the same civil twilight boundaries as EASA — the period between the end of evening civil twilight and the beginning of morning civil twilight. So for logging night flight time, both regulators use the identical −6° standard.

The FAA adds two further concepts NightLog Pro also flags:
  • Position lights (14 CFR 91.209): required from sunset to sunrise (sun at −0.83°), a wider window than civil twilight.
  • Night currency (14 CFR 61.57): takeoffs and landings for passenger currency must occur between 1 hour after sunset and 1 hour before sunrise — a separate rule NightLog Pro does not compute.
What is Civil Twilight?
Civil twilight occurs when the sun is 6 degrees below the horizon. At this point:
  • It's dark enough that artificial lighting is required
  • The horizon is still visible
  • This is the regulatory night standard under both EASA Part-FCL and FAA 14 CFR 1.1
  • Always verify calculations with your airline's procedures
  • This tool assists with EASA Part-FCL and FAA Part 61 requirements
  • Keep your official logbook as the primary record
  • Use UTC times consistently for accurate calculations
⚠️ This is an estimate. Positions are sampled every minute along a constant-speed great-circle path. Real routing, winds and climb/descent will move the actual crossings by a few minutes. Always reconcile against your official logbook.

The figure this app gives is the -6° civil-twilight one: EASA Part-FCL and FAA 14 CFR 1.1. The United Kingdom is not on that definition.

  • When the UK retained Part-FCL, point FCL.010 was amended to define night as "the time from half an hour after sunset until half an hour before sunrise (both times inclusive), sunset and sunrise being determined at surface level" - the Aviation Safety (Amendment etc.) (EU Exit) Regulations 2019. The same wording is in the Air Navigation Order 2016, Schedule 1.
  • Civil twilight ends roughly 30 minutes after sunset at UK latitudes, so the two definitions are close but not equal - and the gap grows in summer and further north. A flight spanning dusk and dawn can differ by half an hour or more.
  • NightLog Pro does not compute the UK definition. If you log under a UK licence, read this figure as the EASA/FAA one and work your night out from sunset and sunrise instead - the Airport Solar Data section gives both.
⚠️ UK SERA keeps the ICAO civil-twilight definition for airspace rules, but the licensing definition above is the one a UK logbook follows.
At cruise altitude the visible horizon dips below the geometric horizon. At FL350 the dip is approximately 3.3°. This means the sun stays above your visible horizon slightly longer, so civil twilight and sunset occur later from your perspective, shortening the calculated night time.

Is it required?
No. EASA Part-FCL and FAA 14 CFR 1.1 define night based on surface-level civil twilight, not aircraft altitude. For regulatory logbook purposes, leave Flight Level blank. The standard calculation is what your authority expects.
💡 Enter a Flight Level only if you want a physically accurate estimate of darkness at cruise altitude. It does not change your regulatory night time obligation.
Supported Browsers:
  • ✅ Chrome / Edge (Recommended)
  • ✅ Firefox
  • ✅ Safari
  • ✅ Mobile browsers (iOS Safari, Chrome Mobile)
Troubleshooting:
  • Ensure internet connection for CDN libraries
  • All times must be in UTC format
  • Type at least 2 characters for airport search
Privacy Policy
Last updated: 1 September 2026 · Full policy

Data We Collect
  • NightLog Pro does not collect, store, or transmit any personal data to external servers.
  • All flight calculations are performed entirely on your device. No flight data, times, or airport selections leave your device.
  • Recent calculations are saved to this device's local storage only. They are never sent anywhere.
Third-Party Services
  • This app — calculates entirely offline and contacts no third party. The engine, the airport database and the world map are bundled inside it. It sends one thing: anonymous counts — counter names and whole numbers, never your flights — to NightLog Pro's own server, which you can switch off in Settings.
  • The website only — nightlogpro.com loads anonymised performance metrics via Vercel Analytics (no personally identifiable information), and the results map draws its background from CARTO, which receives your IP address as any web server would. The website also keeps anonymous daily totals of its own — how many calculations were run, whether visitors return, which error messages people hit, and thumbs up/down on a result — with no cookie and no identifier of any kind.
  • Everything else is self-hosted. Fonts, icons, the mapping library, the astronomical engine and the airport database are all served from nightlogpro.com itself — no other third party sees your visit.
  • The Android testing links are shown only to people sent an invite link, and point at a Google Group and at Google Play. Nothing is sent when the page loads; only if you choose to follow them and join does Google receive your email address, under their privacy policy. NightLog Pro never sees it.
Cookies
  • NightLog Pro does not use cookies.
📬 Contact & Enquiries
For questions, feedback, or privacy concerns, please reach out at:
nightlogpro@gmail.com