Thread: Calendar Program. What am I doing wrong?

Hey everyone. I'm typing up a program which prints out a calendar for any month and year (starting with 1 A D) which the user inputs. I found a general algorithm for calculating the first day of the month but when i cout it in my if statements, something's wrong. It prints out | | 1 no matter what B is equal to. The algorithm is

1) Subtract 1 from the year and store the result in a variable A.
2) Multiply A by 365
3) Find the quotient when you divide the (year - 1) by 4 (ignore remaindr) and add this to A
4) Find the quotient when you divide the (year - 1) by 100 (ignore the remainder) and subtract this from A.
5) Find the quotient when you divide the (year - 1) by 400 (ignore the remainder) and add this to A.
6) Add the days in the year prior to this month (dont worry about leap years here) to A.
7) Add 1 to A (for first day of month)
8) If the year is a leap year and the month is after February add 1 to A. Note: A year is a leap year if it is divisible by 4 AND if it is not a centennial OR it is a centennial divisible by 400.
9) Find the remainder when dividing A by 7

Here's my code so far:

Code:

// Calendar Project
// Ez Nadar

#include <iostream>

using std::cin;
using std::cout;
using std::endl;

int day(int year, int month);
int daysbefore(int month);
int main()
{
	int month = 0, year = 0, d = 0, b = 0;



	cout << "Enter the year of the calendar" << endl;
	cin >> year;
	cout << "Enter the month of the calendar" << endl;
	cin >> month;

	d = daysbefore(month);
	b = day(year, month);

	if ( month == 12)
		cout << "		     " << "Calendar of December " << year << endl;

	if ( month == 11)
		cout << "		     " << "Calendar of November " << year << endl;

	if ( month == 10)
		cout << "		     " << "Calendar of October " << year << endl;

	if ( month == 9)
		cout << "		     " << "Calendar of September " << year << endl;

	if ( month == 8)
		cout << "		     " << "Calendar of August " << year << endl;

	if ( month == 7)
		cout << "		     " << "Calendar of July " << year << endl;

	if ( month == 6)
		cout << "		     " << "Calendar of June " << year << endl;

	if ( month == 5)
		cout << "		     " << "Calendar of May " << year << endl;

	if ( month == 4)
		cout << "		     " << "Calendar of April " << year << endl;

	if ( month == 3)
		cout << "		     " << "Calendar of March " << year << endl;

	if ( month == 2)
		cout << "	         " << "Calendar of February " << year << endl;

	if ( month == 1)
		cout << "		     " << "Calendar of January " << year << endl;

	cout << "	    ----------------------------------------- " << endl;
	cout << "	   | Sun | Mon | Tue | Wed | Thu | Fri | Sat |" << endl;
	cout << "	    ----------------------------------------- " << endl;

	if ( b = 0)

	cout << "	   |    1|";

	else if ( b = 1)

	cout << "	   |	 |	  1|";

	else if ( b = 2)

	cout << "	   |	 |	   |  1|";

	else if ( b = 3)

	cout << "	   |	 |	   |	 |	  1|";

	else if ( b = 4)

	cout << "	   |	 |	   |	 |	   |    1|";
	else if ( b = 5)

	cout << "	   |	 |	   |	 |	   |     |	  1|";
		
	else if ( b = 6)

	cout << "	   |	 |	   |	 |	   |     |	   |    1|";
	return 0;
}
int  daysbefore(int month) // calculates days in the year before this month
{
	int d = 0;

	if ( month == 12)
	d = 334;

	if ( month == 11)
	d = 304;

	if ( month == 10)
	d = 273;

	if ( month == 9)
	d = 243;

	if ( month == 8)
	d = 212;

	if ( month == 7)
	d = 181;

	if ( month == 6)
	d = 151;

	if ( month == 5)
	d = 120;

	if ( month == 4)
	d = 90;

	if ( month == 3)
	d = 59;

	if ( month == 2)
	d = 31;

	if ( month == 1)
	d = 0;

	return d;
}
int day(int year, int month) // determines first day of month
{
	int a = 0, b = 0;
a = year - 1;
a = a * 365;
a = a + ((year - 1) / 4);
a = a - ((year - 1) / 100);
a = a + ((year - 1) / 400);
a = a + daysbefore(month);
a = a + 1;

if ( ( year % 100 ) != 0 )

	if ( (year % 4) != 0 )
	{
		a = a + 1;
	}

b = (a%7);
return b;
}

I know the spacing is off in my cout statements

For those if statements involving b, you're using the assignment operator = instead of the comparison operator ==.

Also, read up on switch. That would help you here.

ohh, thanks . It's always good to have another pair of eyes . Yeah, ill follow up on the switches. thanks for the tip!

I just switched the '=' to '==' but now none of the values of b are couting . I dont know why

You're welcome.