5. Step in the right direction

• Since we found a way to replace "3/8/2010" with int representation, making calculations and comparing dates becomes easy:

  
          serial_date = serial_date + 100; // add 100 days
  
          if ( serial_date < today ) {     // compare dates
              // the date is in the past ("less than today")
              // ...
          }
  
          int age = serial_2_year( today ) - serial_2_year( serial_date );