Water-Skiing
All around white light must be displayed between sunset and sunrise.
1 hour after sunset to 1 hour before sunrise
At the north pole, there was no sunrise on that date. At the south pole, there was no sunset. Anywhere in between, the times of sunrise and sunset depended on the latitude of the location.
In the broadest sense, that interval is generally referred to as "night".
Sunrise to sunset. It is illegal to tow a skier or similar device between sunset and sunrise.
Night is the period of time between sunset and sunrise.
That it's dark and that it occurs between sunset and sunrise.
"daylight" (hours)
The hours between sunrise and sunset.
Sunrise = Alba, Sunset = tramonto
The period of darkness between sunset and sunrise