day off vs working time

day off

noun
  • A day of vacation; a day when one does not go to work, school, etc. 

working time

noun
  • The period of time that an individual spends at paid occupational labor. Most countries regulate the working time by law, e.g. by stipulating a maximum number of working hours per week. Exact definition varies by the legislation. 

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