notice vs observance

notice

noun
  • The act of observing; perception. 

  • A published critical review of a play or the like. 

  • A written or printed announcement. 

  • Advance notification of termination of employment, given by an employer to an employee or vice versa. 

  • A formal notification or warning. 

  • Prior notification. 

verb
  • To be noticeable; to show. 

  • To become aware of; to observe. 

observance

noun
  • Observation or the act of watching. 

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

  • That which is to be observed. 

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

  • The custom of celebrating a holiday or similar occasion. 

  • Reverence; homage. 

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