solar day vs while

solar day

noun
  • one day of solar time, the time between successive noons; the time in which a planet such as Earth apparently rotates once around its axis, relative to the sun (on Earth about 24 hours as an average - the length of solar day is not constant throughout the year) 

while

noun
  • An uncertain duration of time, a period of time. 

  • an uncertain long period of time 

  • an uncertain short moment 

prep
  • Until. 

conj
  • As long as. 

  • Until. 

  • During the same time that. 

  • Used to denote an individual experiencing racial profiling when performing a seemingly benign activity. 

  • Although. 

verb
  • To pass (time) idly. 

  • To occupy or entertain (someone) in order to let time pass. 

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