happy hour vs hiatus

happy hour

noun
  • Any small gathering, usually in the afternoon or early evening, set aside to relax and have a drink. 

  • A time of day, usually in the afternoon or early evening, when a bar or pub offers its drinks at a discounted price. 

  • Flowers. 

hiatus

noun
  • An interruption, break or pause. 

  • A gap in a series, making it incomplete. 

  • An opening in an organ. 

  • A gap in geological strata. 

  • A syllable break between two vowels, without an intervening consonant. (Compare diphthong.) 

  • An unexpected break from work. 

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