The Dusk to Dawn Ride begins at sunset. This is just the beginning of a long procession to the dark.

The passage from day to night is a process - not an event. Nothing is ever simple about the transition from light to dark. It’s never black and white.

These are the four most common aspects of the transition from light to night are:

Sunset is the moment when the top most surface of the sun dips under the horizon.
Twilight is the time between sunset and dusk.
Dusk is the moment when the sun reaches 18 degrees below the horizon.
Night begins when twilight ends.

And of course there are three layers of dusk. More on this later.