plain as day vs straightforward

plain as day

adj
  • Very clear and evident. 

straightforward

adj
  • direct; forthright; frank; sincere 

  • proceeding in a straight course or manner; not deviating 

  • easy, simple, uncomplicated, without difficulty 

adv
  • In a straightforward manner; straightforwards; straightforwardly. 

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