Night time calculator
Calculate EASA-compliant night time for any flight leg. Enter your route and UTC block times — get the result in HH:MM with takeoff and landing classification. Free, no account required.
⚠️ Enter off-block and on-block in UTC, not local time. Night time is always computed in UTC regardless of airport local time zones.
What you are measuring
The EASA definition of night
Under EASA regulations, night is defined as the period from the end of evening civil twilight to the beginning of morning civil twilight. Civil twilight occurs when the centre of the sun is 6° below the geometric horizon — roughly 20 to 30 minutes after the sun's disc has set and before it rises, depending on latitude and season.
This differs from the sunset-to-sunrise definition used in some other jurisdictions, where night begins the moment the sun's upper edge touches the horizon. The civil twilight threshold gives a slightly narrower night window, which matters when checking whether a takeoff or landing qualifies as night for currency or logbook purposes.
Why the route matters
A flight does not experience the same lighting conditions throughout. A sector departing at dusk may be in night conditions for part of the cruise, and arrive after sunrise. Or a long polar route may stay in darkness for hours even in summer.
This tool tracks the aircraft's position along the great-circle path, checking the sun's altitude every minute. Night time is accumulated only during minutes when the sun is below the civil twilight threshold at the aircraft's current position. The result reflects what actually happened along that specific route on that specific date — not a fixed point measurement at origin or destination alone.
Block time includes taxi
The calculation uses off-block and on-block times — the moment the aircraft pushes back (or begins moving under its own power) to the moment the parking brake is set. Night time accumulated during taxi before takeoff or after landing is therefore included in the result, consistent with how block time is recorded in a logbook.
Limitations
- Great-circle approximation. Position is interpolated linearly between origin and destination. Actual filed routes deviate from the great circle; the difference is typically small for medium-haul sectors.
- UTC times required. All times must be entered in UTC. If you enter local times, the result will be incorrect.
- Airports must be in the database. The calculation relies on airport coordinates. Airports not in the search database cannot be used.
- Indicative result only. This tool is designed to help pilots understand and cross-check their logbook entries. It is not a certified dosimetry or compliance record. Your company software or the relevant authority tool is the definitive source.
Night time computed using the SunCalc library (V. Agafonkin). EASA civil twilight definition: sun centre below −6° geometric horizon.