schedule vs sign on

schedule

verb
  • To add a name to the list of people who are participating in something. 

  • To plan an activity at a specific date or time in the future. 

  • To create a time-schedule. 

  • To admit (a person) to hospital as an involuntary patient under a schedule of the applicable mental health law. 

noun
  • A written or printed table of information, often forming an annex or appendix to a statute or other regulatory instrument, or to a legal contract. 

  • A serial record of items, systematically arranged. 

  • One of the five divisions into which controlled drugs are classified, or the restrictions denoted by such classification. 

  • An allocation or ordering of a set of tasks on one or several resources. 

  • A procedural plan, usually but not necessarily tabular in nature, indicating a sequence of operations and the planned times at which those operations are to occur. 

sign on

verb
  • To commit oneself, as to a project, a goal, an organization, a cause. 

  • To begin broadcasting a radio or television signal, usually at the beginning of a broadcasting day and after being off the air for several hours. 

  • To join something, after signing. 

  • To apply to receive unemployment benefits. 

  • To log on; to start using a computer, radio, etc., or to start talking. 

noun
  • The time of day when a radio or television station begins broadcasting, usually after being off the air for several hours. 

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