Thread: wrong answer?

the program is meant to output 31 days
why does it output 30 days?
what have i done wrong

Code:

int main()
{
	int month, days;

	month = 7;
	
	if (month == 2) { 
		days = 28;
	}
	else if (month == 4 || 6 || 9 || 11 ) {
		days = 30;
	}
	else {
		days = 31;

	}	
	
	printf( "days=%d\n", days );

	return 0;
}