Night
Depending on the context, the FAA has several definitions of "night".
For logging night time
Night time may be logged between the end of evening civil twilight and the start of morning civil twilight.
14 CFR 1For logging takeoffs and landings at night
To meet recent experience requirements, takeoffs and landings at night must be made between:
- 1 hour after sunset, to
- 1 hour before sunrise
For Position Lights
An aircraft's position lights shall be operated between sunset and sunrise.
91.209