The word is derived from the Old English ?fnung, 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.
Some languages that use the time of day in greeting have a special greeting for the evening, such as the English "good evening".
Typically people do not leave somebody and say "good evening". Even if it isn't night yet when one greets someone, they can greet them with "good evening" and when they leave, they say "good night", rather than saying "good evening" as a farewell, despite that it may still be evening.
Many people greet someone with the shortened "evening" rather than "good evening". Social and family activities are often held during this time, such as supper or more formal social gatherings and entertainment, such as parties, in particular, dance parties.