civil twilight： what does civil mean in here？ civil twilight： what does civil mean in here？ Can anyone tell me why you use civil in here?Civil twilight occurs when the Sun is less than 6 degrees below the horizon. In the morning, civil twilight begins when the Sun is 6 degrees below the horizon and ends at sunrise. In the evening, it begins at sunset and ends when the Sun reaches 6 degrees below the horizon.