Evening



Evening is the period of a day that begins at the end of daylight and overlaps with the beginning of night. It generally indicates the period of time when the sun is close to the horizon and comprises the periods of civil, nautical and astronomical twilight. The exact times when evening begins and ends are subjective and depend on location and time of year. It may be used colloquially to include the last waning daytime shortly before sunset.

Etymology
The word is derived from the Old English ǣfnung, meaning 'the coming of evening, sunset, time around sunset', which originated from æfnian, meaning "become evening, grow toward evening". The Old English æfnian originated from æfen (eve), which meant "the time between sunset and darkness", and was synonymous with even (Old English æfen), which meant the end of the day. The use of "evening" dates from the mid 15th century.

Start time
The Encyclopædia Britannica defines evening as varying according to daylight and lifestyle, but says that many people consider it to begin at 4 p.m.

In a social context, the Oxford English Dictionary defines evening as "the time from about 6 p.m., or sunset if earlier".

As such there is no fixed consensus on when the period of evening starts.

Astronomy
Despite the less favorable lighting conditions for optical astronomy, evening can be useful for observing objects orbiting close to the Sun. Evening (and morning) serves as the optimum time for viewing the inferior planets Venus and Mercury. It is a popular time to hunt for comets, as their tails grow more prominent as these objects draw closer to the Sun. The evening (and morning) twilight is used to search for near-Earth asteroids that orbit inside the orbit of the Earth. In mid-latitudes, spring evenings around the time of the equinox―that is, the March one in the Northern Hemisphere and the September equinox to the south of the equator―are favorable for viewing the zodiacal light.