observance vs remembrance

observance

noun
  • Reverence; homage. 

  • The practice of complying with a law, custom, command or rule. 

  • That which is to be observed. 

  • Observation or the act of watching. 

  • A rule governing a religious order, especially in the Roman Catholic church. 

  • The custom of celebrating a holiday or similar occasion. 

remembrance

noun
  • That which serves to keep in or bring to mind; a memento, a memorial, a souvenir, a token; a memorandum or note of something to be remembered. 

  • The act of remembering; a holding in mind, or bringing to mind; recollection. 

  • Something remembered; a person or thing kept in memory. 

  • The power of remembering; the reach of personal knowledge; the period over which one's memory extends. 

  • The state of being remembered, or held in mind; memory, recollection. 

verb
  • To remember; to recall to mind. 

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