greeting vs have a nice day

greeting

noun
  • The action of the verb to greet. 

  • A conventional phrase used to start a letter or conversation or otherwise to acknowledge a person's arrival or presence. 

have a nice day

phrase
  • . A polite parting during daytime. 

  • Used other than figuratively or idiomatically: see have, a, nice, day. 

How often have the words greeting and have a nice day occurred in a corpus of books? (source: Google Ngram Viewer )