In Paris you would say, "bonne nuit."
An example of bonne nuit is what someone would say before going to bed in France.
"bonne nuit." YourDictionary, n.d. Web. 17 August 2018. <http://www.yourdictionary.com/bonne-nuit>.
bonne nuit. (n.d.). Retrieved August 17th, 2018, from http://www.yourdictionary.com/bonne-nuit
Origin of bonne nuit