due date vs maturity date

due date

noun
  • The date of payment in financial arrangements. 

  • The date on which a pregnant woman is expected to give birth. 

  • The date by which a book (or other item) borrowed from a library must be returned. 

  • The date by which a task is supposed to be completed. 

maturity date

noun
  • The date on which a principal amount of a note, draft, acceptance bond, or other debt instrument becomes due or payable. 

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