5.9

#include<iostream>

using namespace std;

class Time;

class Date {

public:

    Date(int, int, int);

    void display(Time&);

private:

    int year, month, day;

};

class Time {

public:

    Time(int, int, int);

    friend Date;

private:

    int hour, minu, sec;

};

Time::Time(int h, int m, int s) {

    hour = h; minu = m; sec = s;

}

Date::Date(int y, int m, int d) {

    year = y; month = m; day = d;

}

void Date::display(Time& t) {

    cout << year << "/" << month << "/" << day << endl;

    cout << t.hour << ":" << t.minu << ":" << t.sec << endl;

}

void main() {

    Date d1(2014, 2, 5);

    Time t1(11, 1, 1);

    d1.display(t1);

}