Assignment 96

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();
    
    		// put a function call for weekday() here
            
            String birthday = weekday(mm,dd,yyyy) + ", " + month_name(mm) + " " + dd + ", " + yyyy;
            
    		System.out.println("You were born on " + birthday + "!");
    	}
    
    
    	public static String weekday( int mm, int dd, int yyyy )
    	{
    		int yy, total;
    		String date = "";
    
    		// bunch of calculations go here
            
            yy = yyyy - 1900;
            total = yy / 4;
            total = total + yy;
            total = dd + total;
            total = total + monthOffset(mm);
            
            if ( isLeap(yyyy) == true && month_name(mm) == "January" || month_name(mm) == "February" )
                total = total - 1;
            
            total = total % 7;
            
            date = weekday_name(total);
    		
    		return date;
    	}
    
    
    	// paste your functions from MonthName, WeekdayName, and MonthOffset here
        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 int monthOffset( int month )
    	{
    		int result = 0;
            
            if ( month == 1 )
                result = 1;
            if ( month == 2 )
                result = 4;
            if ( month == 3 )
                result = 4;
            if ( month == 4 )
                result = 0;
            if ( month == 5 )
                result = 2;
            if ( month == 6 )
                result = 5;
            if ( month == 7 )
                result = 0;
            if ( month == 8 )
                result = 3;
            if ( month == 9 )
                result = 6;
            if ( month == 10 )
                result = 1;
            if ( month == 11 )
                result = 4;
            if ( month == 12 )
                result = 6;
            if ( month > 12 || month < 1 )
                result = -1;
    		
    		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 )
    	{
    		// 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 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