Date function: urgent : please help

Question

This is the problem statement.:
Problem: Given two dates (during the years 1901 and 2999, inclusive), find
the number of days between the two dates.
Input: Two dates consisting of month, day, year. For example, the inputs
'6, 2, 1983' and '6, 22, 1983' represent the date range June 2, 1983 to
June 22, 1983.
Output: The number of days between the given dates, excluding the starting
date and the ending date. For example, there are 19 days between June 2,
1983 and June 22, 1983; namely, June 3, 4, ..., 21.
Test Input (3 sets):
Input Line #1: 6, 2, 1983, 6, 22, 1983
Output #1: 19
Input Line #2: 7, 4, 1984, 12, 25, 1984
Output #2: 173
Input Line #3: 1, 3, 1989, 3, 8, 1983
Output #3: 1979
==========
I have a GregorianCalender function that works. But I want to use a basic java function that can solve the above problem.
regards
~m

Answer 1

Here is the code that uses the Gregorian Funtion. Does anybody know of anything basic that replaces what gregorian does in this case.
import java.util.*;
import java.io.*;
import java.math.*;
import java.text.*;
import java.lang.*;
public class Days {
     static int year1,month1,day1;
     static int year2,month2,day2;
     public static void main(String[] args) throws Exception{
          parse(args);
          GregorianCalendar gc1 = new GregorianCalendar(year1, day1, month1);
          GregorianCalendar gc2 = new GregorianCalendar(year2, day2, month2);
          DateFormat df1 = DateFormat.getDateInstance();
          DateFormat df2 = DateFormat.getDateInstance();
          try {
               Days ds = new Days();
               ds.getDays(gc1, gc2);
               System.out.println("Output #: " + (ds.getDays(gc1, gc2) - 1));
          } catch (java.lang.IllegalArgumentException e) {
               System.out.println("Unable to parse");
     // validate input values,
          // if input parameters are not correct and not in a proper format
          // then throw an exception
     private static void parse(String[] args) throws Exception{
          boolean flag = true;
          if(args == null) output();
          if(args != null && args.length != 2) output();
          validate(args);
          return;
     private static void output() throws Exception{
               throw new Exception("Input arguments are not correct. You should pass "+
                                        "two input dates with a space such as 1901,1,1 2999,1,1");
     private static void validate(String[] args) throws Exception{
          String arg1 = args[0];
          String arg2 = args[1];
          System.out.println(arg1);
          System.out.println(arg2);
          java.util.StringTokenizer tokenizer = new StringTokenizer(arg1,",");
          if(tokenizer.countTokens() < 3) output();
          String year1AsString = tokenizer.nextToken(",");
          String month1AsString = tokenizer.nextToken(",");
          String day1AsString = tokenizer.nextToken(",");
          year1 = getInt(year1AsString,4);
          month1 = getInt(month1AsString,2);
          day1 = getInt(day1AsString,2);
          java.util.StringTokenizer tokenizer2 = new StringTokenizer(arg2,",");
          if(tokenizer2.countTokens() < 3) output();
          String year2AsString = tokenizer2.nextToken(",");
          String month2AsString = tokenizer2.nextToken(",");
          String day2AsString = tokenizer2.nextToken(",");
          year2 = getInt(year2AsString,4);
          month2 = getInt(month2AsString,2);
          day2 = getInt(day2AsString,2);
     private static int getInt(String string, int maxLimit) throws Exception{
          if(string.length() > maxLimit) output();
          int temp = 0;
          try{
               temp = Integer.parseInt(string);
          }catch(NumberFormatException e){
               output();
          return temp;
     public int getDays(GregorianCalendar g1, GregorianCalendar g2) {
          int elapsed = 0;
          GregorianCalendar gc1, gc2;
          if (g2.after(g1)) {
               gc2 = (GregorianCalendar) g2.clone();
               gc1 = (GregorianCalendar) g1.clone();
          } else {
               gc2 = (GregorianCalendar) g1.clone();
               gc1 = (GregorianCalendar) g2.clone();
          gc1.clear(Calendar.MILLISECOND);
          gc1.clear(Calendar.SECOND);
          gc1.clear(Calendar.MINUTE);
          gc1.clear(Calendar.HOUR_OF_DAY);
          gc2.clear(Calendar.MILLISECOND);
          gc2.clear(Calendar.SECOND);
          gc2.clear(Calendar.MINUTE);
          gc2.clear(Calendar.HOUR_OF_DAY);
          while (gc1.before(gc2)) {
               gc1.add(Calendar.DATE, 1);
               elapsed++;
          return elapsed;
~m