constantly vs from day to day

constantly

adv
  • Recurring regularly. 

  • In an unchangeable or invariable manner; in every case. 

  • In a constant manner; occurring continuously; persistently. 

from day to day

adv
  • daily. 

  • focusing on one day at a time. 

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