Sundown, one, the time it disappears.
Gloaming, two, the twilight, dusk.
Crepuscule, the twilight, three, the half-light.
Twilight, four, pale purplish blue to pale violet, lighter than dusk blue.
Civil twilight, until the sun is up to six degrees below horizon.
Enough light on clear days for ordinary occupations.
Nautical twilight, until the sun is up to twelve degrees below horizon.
Astronomical twilight, until the sun is eighteen degrees down,
More or less.
Clair de lune, five, greener and paler than dusk.
Dusk, six, redder and darker than clair de lune.
Dear George,
What's going on?
I'm not the same person that I used to be.