Используется неинициализированная локальная переменная tc ( ошибка)

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struct dat
{
	int day;
int month;
		int year;
		int cday;
			int cmonth;
			int cyear;
};
void dob()
{
	dat d;

	cout << " enter date of birth";
	
		cout << endl;
	
		cout << " enter day";
		cin >> d.day;
		cout << endl;
		cout << " month";
		cin >>d.month;
		cout << endl;
		cout << "year";
		cin >> d.year;
		cout << endl;
		cout <<d. day << "-" << d.month << "-" <<d.year;
		cout << endl; cout << endl;
}
void cdob()
{
	dat cd;

	cout << " enter  current date ";

	cout << endl;

	cout << " enter day";
	cin >> cd.day;
	cout << endl;
	cout << " month";
	cin >> cd.month;
	cout << endl;
	cout << "year";
	cin >> cd.year;
	cout << endl;
	cout << cd.day << "-" << cd.month << "-" << cd.year;
	cout << endl; cout << endl;
}
void tdob()
{
	dat tc;
	int tyear;
		tyear = tc.cyear - tc.year-1;
		int  days;
		days = tc.day - tc.cday;
		int tmonth;
		tmonth = tc.month + tc.cmonth;
		cout << " year = " << tyear;
		cout << endl;
		cout << " total days" << days;
		cout << endl;
		cout << "total month" << tmonth;
		cout << endl;


}
void main()
{
	dob();
	cdob();
	tdob();
}

Что я уже пробовал:

void tdob()
{
	dat tc;
	int tyear;
		tyear = tc.cyear - tc.year-1;
		int  days;
		days = tc.day - tc.cday;
		int tmonth;
		tmonth = tc.month + tc.cmonth;
		cout << " year = " << tyear;
		cout << endl;
		cout << " total days" << days;
		cout << endl;
		cout << "total month" << tmonth;
		cout << endl;
}

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