by God vs heyday

by God

intj
  • An exclamation of surprise. 

adj
  • Genuine, actual. 

adv
  • Used as an oath to emphasize the veracity of an associated statement. 

  • Used as an intensifier. 

heyday

noun
  • A period of success, popularity, or power; prime. 

intj
  • A lively greeting. 

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