dinnertime vs suppertime

dinnertime

noun

  • The time when dinner takes place. 

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

suppertime

noun

  • The time when supper takes place. 

  • The time when supper is ready. 

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