sundial vs timekeeper

sundial

noun
  • A device measuring the time of day by the position of a shadow cast by a pole or plate (gnomon) upon an engraved series of marks. 

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 sundial and timekeeper occurred in a corpus of books? (source: Google Ngram Viewer )