Twilight Time
Evening is the position just before nightfall at dusk, just moments after sunset. In the language of astronomy, evening is the time which occurs just after sunset and just before night .The sky is clear in the middle of the evening when there may be enough light to read outside without artificial lighting .
Towards the end of the evening, when the earth is at a point where its center is 6 degrees to the local horizon , nothing can be read outside, artificial lighting is required.
The term twilight or evening is usually astronomical evening.Or refers to the dark position of twilight before the night begins.
Evening is the last moment of astronomical twilight in time. Twilight is the temporal position before noticing the minimum brightness of the night sky.However, the evening can be divided into three levels.
Early or Civil Evening: At this time the sun is at 6 degrees below the horizon. This position starts from the time of sunset. At this point, different objects in the sky (such as stars) begin to be visible to the naked eye, depending on the weather conditions. Different colors like orange and red can be seen in the sky at this time. Depending on the weather conditions and location, artificial lighting may be required outside the house.
Nautical Evening: In this case the sun apparently moves 12 degrees below the horizon in the evening. At this moment the stars and planets in the sky became brighter.
Astronomy Evening, simply known as evening: At this time the sun is at 16 degrees below the horizon. From this time the evening begins. After this time the sun no longer illuminates the sky.