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Guide

UK licence night: the 30-minute rule

A UK licence does not use the civil-twilight night of EASA and the FAA. It counts from half an hour after sunset to half an hour before sunrise. The two are close, but not the same, and the gap can be large in summer and in the north.

In short

The UK rule: night is from half an hour after sunset until half an hour before sunrise, with sunset and sunrise at surface level.

EASA and FAA: night is the sun more than 6° below the horizon. At UK latitudes civil twilight lasts more than half an hour, and well over an hour in the north at midsummer, so the UK figure is usually the longer one, and the two can differ by half an hour or more.

01 The rule

When the UK retained Part-FCL, point FCL.010 was amended by the Aviation Safety (Amendment etc.) (EU Exit) Regulations 2019 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 same wording is in the Air Navigation Order 2016, Schedule 1. UK SERA keeps the ICAO civil-twilight definition for airspace rules, but the licensing definition above is the one a UK logbook follows.

02 How far apart the two can be

Civil twilight lasts longer in summer and further from the equator, while the UK rule always adds exactly half an hour. So the gap moves with the season and the route:

The same flights, counted both ways at the point below the aircraft
FlightEASA / FAA (−6°)UK licence
EGPH → EGPB
21 Jun 2026, 21:00–23:00Z		0:001:18
EGLL → KJFK
21 Dec 2026, 15:00–23:00Z		2:563:38

Edinburgh to Sumburgh at midsummer: flying north, the sun never gets 6° below the horizon along the route, so there is no civil-twilight night at all, yet more than an hour counts as UK night.

03 Where it is measured

  • NightLog Pro applies the rule along the route, at the point below the aircraft, the same way it applies the −6° line. A moment counts as UK night when the sun there had set at least half an hour before and will not rise for at least half an hour after.
  • The rule does not say where “surface level” is for an aircraft in flight. Measured at the departure and arrival airfields instead, a long flight can differ, most of all westbound in the evening, when the aircraft keeps pace with the sunset. On a circuit or a short sector the two readings agree.
  • Sunset and sunrise are at surface level, so a Flight Level never changes the UK figure.

04 Work it out for your flight

Every result in NightLog Pro gives the UK figure as “UK Licence Night” beside the block time, next to the EASA and FAA night. If your examiner reads the rule at the airfields, the Airport Solar Data gives sunset and sunrise at both ends.

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