fortnightly vs from day to day

fortnightly

adv

  • once in a fortnight; once every two weeks 

adj

  • occurring once in a fortnight; once every two weeks 

noun

  • A publication issued fortnightly (once every two weeks). 

from day to day

adv

  • focusing on one day at a time. 

  • daily. 

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