annual leave vs vacation day

annual leave

noun
  • The use of such days to be away from work; on holiday or vacation. 

  • Amount of time expressed as the number of days per year that an employee is entitled to be away from work. 

vacation day

noun
  • A day when one is permitted to not attend work in order to go on a vacation or attend to other matters. 

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