time of day vs timer

time of day

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

  • The time according to the clock. 

  • The greeting appropriate to the time of day. 

timer

noun
  • One characterized by a certain time or time frame, such as their work hours. 

  • Any electronic function that causes a device to be able to do something automatically after a preset amount of time. 

  • A device used to measure amounts of time. 

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

  • One who has done something a certain number of times. 

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