Assignment #96: Weekday Calculator

Code

import java.util.Scanner;

public class WeekdayCalculator
{
	public static void main( String[] args )
	{
		Scanner keyboard = new Scanner(System.in);

		System.out.println("Welcome to Mr. Davis's fantastic birth-o-meter!");
		System.out.println();
		System.out.println("All you have to do is enter your birth date, and it will");
		System.out.println("tell you the day of the week on which you were born.");
		System.out.println();
		System.out.println("Some automatic tests....");
		System.out.println("12 10 2003 => " + weekday(12,10,2003));
		System.out.println(" 2 13 1976 => " + weekday(2,13,1976));
		System.out.println(" 2 13 1977 => " + weekday(2,13,1977));
		System.out.println(" 7  2 1974 => " + weekday(7,2,1974));
		System.out.println(" 1 15 2003 => " + weekday(1,15,2003));
		System.out.println("10 13 2000 => " + weekday(10,13,2000));
		System.out.println();

		System.out.println("Now it's your turn!  What's your birthday?");
		System.out.print("Birth date (mm dd yyyy): ");
		int mm = keyboard.nextInt();
		int dd = keyboard.nextInt();
		int yyyy = keyboard.nextInt();

		weekday(mm, dd, yyyy);
      
		System.out.println("You were born on " + weekday(mm, dd, yyyy) + "." );
	}


	public static String weekday( int mm, int dd, int yyyy )
	{
		int yy, total;
		String date = "";

		yy = (yyyy - 1900);
      
      total = ((yyyy / 4) + mm + month_offset(mm));
      
      isLeap(yyyy);
      
      if ((isLeap(yyyy)) && ((mm == 1 )||( mm == 2))) {
      
         total = (total - 1);
         
      }
      
      weekday_name(total % 7);

		date = weekday_name(total) + ", " + month_name(mm) + " " + dd + ", " + yyyy;

		return date;
      
	}


	// paste your methods from MonthName, WeekdayName, and MonthOffset here
                                  
    public static String month_name( int mm )
	{
		String resultmonth = "month";
		
		if (mm == 1) {
      
         resultmonth = "January";
         
      }
      
      if (mm == 2) {
      
         resultmonth = "February";
         
      }
      
      if (mm == 3) {
      
         resultmonth = "March";
         
      }
      
      if (mm == 4) {
      
         resultmonth = "April";
         
      }
      
      if (mm == 5) {
      
         resultmonth = "May";
         
      }
      
      if (mm == 6) {
      
         resultmonth = "June";
         
      }
      
      if (mm == 7) {
      
         resultmonth = "July";
         
      }
      
      if (mm == 8) {
      
         resultmonth = "August";
         
      }
      
      if (mm == 9) {
      
         resultmonth = "September";
         
      }
      
      if (mm == 10) {
      
         resultmonth = "October";
         
      }
      
      if (mm == 11) {
      
         resultmonth = "November";
         
      }
      
      if (mm == 12) {
      
         resultmonth = "December";
         
      }
      
      else if (mm > 12) {
      
         resultmonth = "error";
         
      }
      
		return resultmonth;
	}
                                  
    public static String weekday_name( int total ) {
        
        String resultday = "day";
            
        if (total % 7 == 0) {
            
            resultday = "Sunday";
            
        }
        
        if (total % 7 == 1) {
            
            resultday = "Monday";
            
        }
        
        if (total % 7 == 2) {
            
            resultday = "Tuesday";
            
        }
        
        if (total % 7 == 3) {
            
            resultday = "Wednesday";
            
        }
        
        if (total % 7 == 4) {
            
            resultday = "Thursday";
            
        }
        
        if (total % 7 == 5) {
            
            resultday = "Friday";
            
        }
        
        if (total % 7 == 6) {
            
            resultday = "Saturday";
            
        }
        
        return resultday;
        
    }
                                  

	public static int month_offset( int mm ) {
        
      int resultoff = 0;
        
      if (mm == 1) {
      
         resultoff = 1;
         
      }
      
      if (mm == 2) {
      
         resultoff = 4;
         
      }
      
      if (mm == 3) {
      
         resultoff = 4;
         
      }
      
      if (mm == 4) {
      
         resultoff = 0;
         
      }
      
      if (mm == 5) {
      
         resultoff = 2;
         
      }
      
      if (mm == 6) {
      
         resultoff = 5;
         
      }
      
      if (mm == 7) {
      
         resultoff = 0;
         
      }
      
      if (mm == 8) {
      
         resultoff = 3;
         
      }
      
      if (mm == 9) {
      
         resultoff = 6;
         
      }
      
      if (mm == 10) {
      
         resultoff = 1;
         
      }
      
      if (mm == 11) {
      
         resultoff = 4;
         
      }
      
      if (mm == 12) {
      
         resultoff = 6;
         
      }
      
      else if (mm > 12) {
      
         resultoff = -1;
         
      }
		
		return resultoff;
	}
		
	public static boolean isLeap( int year )
	{
		// years which are evenly divisible by 4 are leap years,
		// but years divisible by 100 are not leap years,
		// though years divisible by 400 are leap years
		boolean resultleap;

		if ( year%400 == 0 )
			resultleap = true;
		else if ( year%100 == 0 )
			resultleap = false;
		else if ( year%4 == 0 )
			resultleap = true;
		else
			resultleap = false;
		
		return resultleap;
	}
}

    

Picture of the output