Assignment #96 Weekday Calculator

Code

    /// Name: Koosha Kimelman
    /// Period: 7
    /// Program Name: Weekday Calculator
    /// File Name: WeekdayCalculator.java
    /// Date Completed: 3/17/16
    
    import java.util.Scanner;
    
    public class WeekdayCalculator {
    
    	public static void main( String[] args ) {
        
    		Scanner keyboard = new Scanner(System.in);
    
    		System.out.println("Find out what day of the week you were born.");
    		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_name(weekday(12,10,2003)) + ", December 10, 2003.");
    		System.out.println(" 2 13 1976 => " + weekday_name(weekday(2,13,1976)) + ", February 13, 1976.");
    		System.out.println(" 2 13 1977 => " + weekday_name(weekday(2,13,1977)) + ", February 13, 1977.");
    		System.out.println(" 7  2 1974 => " + weekday_name(weekday(7,2,1974)) + ", July 2, 1974.");
    		System.out.println(" 1 15 2003 => " + weekday_name(weekday(1,15,2003)) + ", January 15, 2003.");
    		System.out.println("10 13 2000 => " + weekday_name(weekday(10,13,2000)) + ", October 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();
    
    		System.out.println("You were born on " + weekday_name(weekday(mm, dd, yyyy)) + ", " + month_name(mm) + " " + dd + ", " + yyyy + ".");
    	}
    
    
    	public static int weekday( int mm, int dd, int yyyy ) {
        
    		int yy, total;
            String date = "";
            
            yy = yyyy - 1900;
            total = yy / 4;
            total = total + yy;
            total = total + dd;
            total = total + month_offset(mm);
            if (isLeap(yyyy) == true && (mm == 1 || mm == 2))
                total--;
            total = total % 7;
    
    		return total;
    	}
        
        public static String weekday_name( int weekday ) {
            
    		String result = "";
    
    		if ( weekday == 1 )
    		{
    			result = "Sunday";
    		}
    		else if ( weekday == 2 )
    		{
    			result = "Monday";
    		}
    		else if ( weekday == 3 )
            {
                result = "Tuesday";
            }
            else if ( weekday == 4 )
            {
                result = "Wednesday";
            }
            else if ( weekday == 5 )
            {
                result = "Thursday";
            }
            else if ( weekday == 6 )
            {
                result = "Friday";
            }
            else if ( weekday == 7 )
            {
                result = "Saturday";
            }
            else if ( weekday == 0 )
            {
                result = "Saturday";
            }
            else
            {
                result = "error";
            }
    		return result;
    	}
        
        public static String month_name(int n) {
            
            String monthName;
            
            if (n == 1)
                monthName = "January";
            else if (n == 2)
                monthName = "February";
            else if (n == 3)
                monthName = "March";
            else if (n == 4)
                monthName = "April";
            else if (n == 5)
                monthName = "May";
            else if (n == 6)
                monthName = "June";
            else if (n == 7)
                monthName = "July";
            else if (n == 8)
                monthName = "August";
            else if (n == 9)
                monthName = "September";
            else if (n == 10)
                monthName = "October";
            else if (n == 11)
                monthName = "November";
            else if (n == 12)
                monthName = "December";
            else
                monthName = "error";
                
            return monthName;
        }
        
        public static int month_offset(int n) {
            
            int monthOffset;
            
            if (n == 1)
                monthOffset = 1;
            else if (n == 2)
                monthOffset = 4;
            else if (n == 3)
                monthOffset = 4;
            else if (n == 4)
                monthOffset = 0;
            else if (n == 5)
                monthOffset = 2;
            else if (n == 6)
                monthOffset = 5;
            else if (n == 7)
                monthOffset = 0;
            else if (n == 8)
                monthOffset = 3;
            else if (n == 9)
                monthOffset = 6;
            else if (n == 10)
                monthOffset = 1;
            else if (n == 11)
                monthOffset = 4;
            else if (n == 12)
                monthOffset = 6;
            else
                monthOffset = -1;
                
            return monthOffset;
        }
    		
    	public static boolean isLeap( int year ) {
        
    		boolean result;
    
    		if ( year%400 == 0 )
    			result = true;
    		else if ( year%100 == 0 )
    			result = false;
    		else if ( year%4 == 0 )
    			result = true;
    		else
    			result = false;
    		
    		return result;
    	}
    }
    

Picture of the output