Assignment #96

Code

    /*
jack newsom
period 5
program WeekdayCalculator
filename WeekdayCalculator.java
date completed 11/2/2015
*/

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