Assignment #96 and WeekdayCalculator

Code

      /// Name: Jason Kim
      /// Period: 7
      /// Program Name: WeekdayCalculator
      /// File Name: WeekdayCalculator.java
      /// Date Finished:1/21/16
      
      import java.util.Scanner;
      
      public class WeekdayCalculator
      {
      	public static void main( String[] args )
      	{
      		Scanner keyboard = new Scanner(System.in);
      
      		System.out.println("Welcome to Jason'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();
      		System.out.println("\nYou were born on " + weekday(mm, dd, yyyy) + "!");
      	}
      
      
      	public static String weekday( int mm, int dd, int yyyy )
      	{
      		int yy = yyyy - 1900, total;
      		String date = "";
              
              total = (yy - yy%4)/4 + yy + dd + monthOffset(mm);
              if ( isLeap(yy) && (mm == 1 || mm == 2))
              {
                  total = total - 1;
              }
      		int remainder = total%7;
              String dayOfWeek = weekday_name (remainder);
      
      		date = dayOfWeek + ", " +  month_name(mm) + " " + dd +", " + yyyy;
      
      		return date;
      	}
      
          public static int monthOffset( int month )
            	{
            		int result;
            		if ( month == 1 )
                    {
                        result = 1;
                    }
                    else if ( month == 2 )
                    {
                        result = 4;
                    }
                    else if ( month == 3 )
                    {
                        result = 4;
                    }
                    else if ( month == 4 )
                    {
                        result = 0;
                    }
                    else if ( month == 5)
                    {
                        result = 2;
                    }
                    else if ( month == 6)
                    {
                        result = 5;
                    }
                    else if ( month == 7)
                    {
                        result = 0;
                    }
                    else if ( month == 8)
                    {
                        result = 3;
                    }
                    else if ( month == 9)
                    {
                        result = 6;
                    }
                    else if ( month == 10)
                    {
                        result = 1;
                    }
                    else if ( month == 11)
                    {
                        result = 4;
                    }
                    else if ( month == 12)
                    {
                        result = 6;
                    }
                    else
                    {
                        result = -1;
                    }
                    
            		return result;
            	}
      
          public static String month_name( int month )
            	{
            		String result;
            		if ( month == 1)
                    {
                        result = "January";
                    }
                    else if ( month == 2)
                    {
                        result = "February";
                    }
                    else if (month == 3)
                    {
                        result = "March";
                    }
                    else if (month == 4)
                    {
                        result = "April";
                    }
                    else if (month == 5)
                    {
                        result = "May";
                    }
                    else if (month == 6)
                    {
                        result = "June";
                    }
                    else if (month == 7)
                    {
                        result = "July";
                    }
                    else if (month == 8)
                    {
                        result = "August";
                    }
                    else if (month == 9)
                    {
                        result = "September";
                    }
                    else if (month == 10)
                    {
                        result = "October";
                    }
                    else if (month == 11)
                    {
                        result = "November";
                    }
                    else if (month == 12)
                    {
                        result = "December";
                    }
                    else 
                    {
                        result = "error";
                    } 
            		return result;
            	}
          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 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