ceremony vs national holiday

ceremony

noun
  • An official gathering to celebrate, commemorate, or otherwise mark some event. 

  • A formal socially established behaviour, often in relation to people of different ranks; formality. 

  • Show of magnificence, display, ostentation. 

  • A ritual, with religious or cultural significance. 

national holiday

noun
  • A public holiday. 

  • A statutory holiday enacted by a country to commemorate the country itself. 

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