digital clock vs timekeeper

digital clock

noun
  • A clock that displays the time (hours, minutes, and sometimes seconds) in digits, rather than by hands on a dial (like a analog clock). 

timekeeper

noun
  • A device that shows the time; a timepiece. 

  • A person (or something controlled by a person) that is or isn't punctual. 

  • A person who keeps records of the hours of attendance of employees. 

  • A person who records the time elapsed in a sporting event. 

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