on time vs time-consuming

on time

adj
  • Punctual or according to schedule. 

prep
  • By installments, payments over a period of time. 

  • By a player's running out of time. 

  • Punctually or according to the schedule. 

time-consuming

adj
  • Using significant amounts of time, especially in an unwanted and sometimes unwarranted manner. 

How often have the words on time and time-consuming occurred in a corpus of books? (source: Google Ngram Viewer )