call it a day vs stand down

call it a day

verb
  • To retire. 

  • To cease the activity for the day. 

stand down

verb
  • To withdraw or retire from a position or from a team. 

  • To wait; to stop pursuing, stop fighting, or relax from a heightened readiness posture. 

How often have the words call it a day and stand down occurred in a corpus of books? (source: Google Ngram Viewer )