due date vs time of day

due date

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

  • 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 of payment in financial arrangements. 

time of day

noun
  • The time according to the clock. 

  • A loosely specified period of time, minutes or hours in duration, especially daytime, or point in time. 

  • The greeting appropriate to the time of day. 

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