Twilight

1. Dusk

1.1. Dusk is the evening twilight

1.2. There is 3 kinds of dusks, there is civil dusk wich is when the sun is exactly 6 degrees below the horizon, there is nautical dusk wich is when the sun is exactly 12 degrees below the horizon, also there is astronomical dusk wich is when the sun is exactly 18 degrees below the horizon

2. Dawn

2.1. Dawn is the morning twilight

2.2. There are 3 different types of dawn, there is civil dawn wich occurs when the sun is less than 6 degrees below the horizon. There is nautical dawn wich occurs when the sun is less than 12 degrees below the horizon. Also there is astronomical dawn wich occurs when the sun is less than 18 degrees below the horizon