An example of buenas noches is what you say to someone when you are retiring to go to bed for the evening.
"buenas noches." YourDictionary, n.d. Web. 15 May 2018. <http://www.yourdictionary.com/buenas-noches>.
buenas noches. (n.d.). Retrieved May 15th, 2018, from http://www.yourdictionary.com/buenas-noches
Origin of buenas noches