dusk vs peep of day

dusk

adj
  • Tending to darkness or blackness; moderately dark or black; dusky. 

verb
  • To begin to lose light or whiteness; to grow dusk. 

  • To make dusk. 

noun
  • A darkish colour. 

  • The condition of being dusky; duskiness 

  • A period of time at the end of day when the sun is below the horizon but before the full onset of night, especially the darker part of twilight. 

peep of day

noun
  • break of day; daybreak 

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