Sentence examples for a good night from inspiring English sources

The phrase "a good night" is correct and usable in written English.
It can be used when wishing someone a pleasant evening or as a farewell at the end of the day.
Example: "As the evening came to a close, I turned to my friends and said, 'I hope you all have a good night.'"
Alternatives: "a pleasant evening" or "a lovely night".