How to calculate total seconds in a year?

Source:

import java.util.*;

public class CalculateSeconds {
   public static void main(String[] args) {

      Calendar cal  = Calendar.getInstance();
      cal.set(Calendar.YEAR, 2013);
      cal.set(Calendar.MONTH, 0);
      cal.set(Calendar.DAY_OF_MONTH, 1);

      cal.set(Calendar.HOUR, 0);
      cal.set(Calendar.MINUTE, 0);
      cal.set(Calendar.SECOND, 0);

      long start = cal.getTimeInMillis();

      // set one year later
      cal.set(Calendar.YEAR, 2014);
      long end = cal.getTimeInMillis();

      long seconds = (end - start) / 1000;
      System.out.println("There are " + seconds + " seconds in the year.");

   }
}

Output:

   $ java CalculateSeconds
   There are 31536000 seconds in the year.