Help me please

[missmango]

Please help me, I try to write a program that includes a user-defined function named dayOfWeek that will take a date as three separate integer arguments representing the month, day and year, and return the day-of-week value as determined by Zeller's method.
The following is my code, but this code does not work for the Feb month, the other months it works well. And also how do I remove the number front the weekday?.
Please help me. Thanks

#include <iostream>
#include <cmath>
using namespace std;

int main()
{
char yesno='y';
while(yesno=='Y' || yesno=='y')
{
int d;
// d = day of the month
int m;
// m = month (3 = March, 4 = April, 5 = May, 6 = June, 7 = July, 8 = August, 9 = September, 10 = October, 11 = November, 12 = December, 13 = Janurary, 14 = February)
int y;
// Year
int k;
// k = year of the century, last two digits.
int j;
// j = century
int dayOfWeek;
// h = day of the week (0 = Saturday, 1 = Sunday, 2 = Monday, 3 = Tuesday, 4 = Wednesday, 5 = Thrusday, 6 = Friday)

cout << "Please enter a date as mm dd yyyy: \n";
cout << "For the month, please note: 3 = March, 4 = April, 5 = May, 6 = June, 7 = July, 8 = August, 9 = September, 10 = October, 11 = November, 12 = December, 13 = Janurary, 14 = February" << endl;
cin >> m >> d >> y;
j = y /100;
k = y % 100;
dayOfWeek = (d + 26 * (m + 1) / 10 + k + k/4 + j/4 + 5*j) % 7;

cout << "This date is on \n"<< dayOfWeek;


switch (dayOfWeek)
{
case 0:
cout << "Saturday\n";
break;
case 1:
cout << "Sunday\n";
break;
case 2:
cout << "Monday\n";
break;
case 3:
cout << "Tuesday\n";
break;
case 4:
cout << "Wednesday\n";
break;
case 5:
cout << "Thursday\n";
break;
case 6:
cout << "Friday\n";
break;
default:
cout << "That is not a possible weekday.\n";
}

cout<<"continue? (y or n) \n";
cin>>yesno;

}
return 0;
}