Friday vs week

Friday

noun
  • The sixth day of the week in many religious traditions, and the fifth day of the week in systems using the ISO 8601 norm; the Muslim Sabbath; it follows Thursday and precedes Saturday. 

  • The last workday in a work schedule that is not Monday through Friday. 

adv
  • On Friday. 

week

noun
  • A period of seven days beginning with Sunday or Monday. 

  • A period of five days beginning with Monday. 

  • A subdivision of the month into longer periods of work days punctuated by shorter weekend periods of days for markets, rest, or religious observation such as a sabbath. 

  • Any period of seven consecutive days. 

adj
  • Seven days after (sometimes before) a specified date. 

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