I followed matsp and kcpilot's advice and changed my code to this:
Code:
#include <iostream>
#include <fstream>
using namespace std;

class Date
{
private:
	int month;
	int day;
	int year;
	static char slash;
public:
	void setDate();
	void showDate();
	void setMonth();
	void setDay();
	void setYear();
};
char Date::slash = '/';
void Date::setDate()
{
	cin  >> month;
	cin.get();
	cin  >> day;
	cin.get();
	cin  >> year;
	cin.get();
}
void Date::setMonth()
{
	if(month > 12 || month == 0)
		month = 12;
	else
		month = month;			
}
void Date::setDay()
{
	if(day > 31 || day == 0)
		day = 31;
	else
		day = day;
}
void Date::setYear()
{
	if(year <= 999 || year > 2500)
		year = 2007;
	else
		year = year;						
}
void Date::showDate()
{
	cout << month << slash << day << slash << year << endl;	
}
void main()
{
	Date aDate[5];
        cout << "Please enter five dates." << endl;
	cout << "You can enter any slashes(/), only numbers(12 3 2007)" << endl;
	ofstream out("H:\\Dates.txt");
	for(int x = 0; x < 5; ++x)
	{
            aDate[x].setDate();
	    aDate[x].setMonth();
	    aDate[x].setDay();
	    aDate[x].setYear();
	    out << aDate[x].month << aDate[x].day << aDate[x].year << endl;
	}
	cout << endl << "The dates you entered were: " << endl << endl;
	for(int x = 0; x < 5; ++x)
		aDate[x].showDate();
	cout << endl;
	system("pause");
}
But then it gives me this error:
Error 1 error C2248: 'Date::month' : cannot access private member declared in class 'Date' h:\documents\c++\oop\program7\program7\program7.cp p 66
Anyway... thanks!