dinnertime vs lunchtime

dinnertime

noun
  • The midday break in English schools (some areas), lunchtime. 

  • The time when dinner takes place. 

lunchtime

noun
  • A break in work or school to eat lunch. 

  • The time or hour at or around which lunch is normally eaten. 

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