everyday vs quotidian

everyday

adj
  • commonplace, ordinary 

  • appropriate for ordinary use, rather than for special occasions 

noun
  • the ordinary or routine day or occasion 

quotidian

adj
  • Having the characteristics of something which can be seen, experienced, etc, every day or very commonly; commonplace, ordinary, mundane. 

  • Recurring every twenty-four hours or (more generally) daily (of symptoms, etc). 

  • Happening every day; daily. 

noun
  • Commonplace or mundane things regarded as a class. 

  • A daily allowance formerly paid to certain members of the clergy. 

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