- Civil. Sun 0-6 degrees below horizon.
- Morning: It's daytime, but the sun's not come up yet.
- Evening: It's still daytime, but it's getting dark.
- Nautical. Sun 6-12 degrees below horizon.
- Morning: It's still dark, but there's light in the sky.
- Evening: It's dark, but there's still light in the sky.
- Astronomical. Sun 12-18 degrees below horizon.
- It's dark, unless you're out in the countryside, in which case if you're away from any artificial lights you might, after a few minutes, perceive some light still in the sky.
Wednesday, June 22, 2016
Twilight
