Pay calculator
Version 1

DESIGN -- DRAFT

Components of the program:

  o A function that runs the calculator

    Implementation note: Delegates the execution of the operations on times to separate functions.
       
  o A structure that stores each time as two integers, one for the hours, one for the minutes.
  
  o Functions for operations on times
  
      - Initializes a time to 99:99.
      - Reads a time from an input stream.
      - Prints a time to an output stream.
      - Computes the difference, in hours, between two times.
      