noon vs oh dark thirty

noon

noun
  • The time of day when the sun is in its zenith; twelve o'clock in the day, midday. 

  • The highest point; culmination. 

  • The letter ن in the Arabic script. 

verb
  • To relax or sleep around midday 

oh dark thirty

noun
  • Some unspecified hour in the early morning (implies an unpleasant time to be awake). 

How often have the words noon and oh dark thirty occurred in a corpus of books? (source: Google Ngram Viewer )