// File Date.cpp
// Implementation file for the Date class
// IEA February 1997
#include <iostream>
#include "Date.h"
using namespace std;
// Constructor functions
Date::Date(int dd,int mm,int yy)
{
    day = dd;
    month = mm;
    year = yy;
}
Date::Date()
{
    day = 1;
    month = 1;
    year = 1900;
}
// Accessor functions
int Date::get_day()
{
    return day;
}
int Date::get_month()
{
    return month;
}
int Date::get_year()
{
    return year;
}
// Other functions
void Date::print()
{
    cout << day << "/" << month << "/" << year;
}
void Date::next_day()
{
    int days_in_month;
    day++;
    switch (month)
    {
        case 1 :
        case 3 :
        case 5 :
        case 7 :
        case 8 :
        case 10:
        case 12: days_in_month = 31;
        break;
        case 4 :
        case 6 :
        case 9 :
        case 11: days_in_month = 30;
        break;
        case 2 : if (leap_year())
        days_in_month = 29;
        else days_in_month = 28;
        break;
    }
    if (day > days_in_month)
    {
        day = 1;
        month++;
        if (month > 12)
        {
            month = 1;
            year++;
        }
    }
}
void Date::week_later()
// This function returns the date a week
// later than date.
{
    Date temp;
    int days_in_month;
    int day,month,year;
    day = date.get_day();
    month = date.get_month();
    year = date.get_year();
    day+= 7;
    switch (month)
    {
        case 1 :
        case 3 :
        case 5 :
        case 7 :
        case 8 :
        case 10:
        case 12: days_in_month = 31;
        break;
        case 4 :
        case 6 :
        case 9 :
        case 11: days_in_month = 30;
        break;
        case 2 : if (leap_year(year))
        days_in_month = 29;
        else days_in_month = 28;
        break;
    }
    if (day > days_in_month) {
        day = day-days_in_month;
        month++;
        if (month > 12) {
            month = 1;
            year++;
        }
    }
    temp = Date(day,month,year);
    return temp;
}
// Private function
int Date::leap_year()
{
    if (year % 400 == 0)
    return 1;
    else if (year % 100 == 0)
    return 0;
    else if (year % 4 == 0)
    return 1;
    else return 0;
}

*****************************

// File Date.h
// Definition file for the class Date
// which represents a simple date class
// IEA February 1997
#ifndef DATE_H
#define DATE_H
class Date
{
    public:
        // Constructors
        // initialise to 1/1/1900
        Date();
        // initialise to dd/mm/yy
        Date(int dd,int mm,int yy);
        // member functions
        void print(); // prints date
        void next_day(); // sets date to next day
        void week_later(); //+7days
        // Accessor functions
        int get_day(); // returns day
        int get_month(); // returns month
        int get_year(); // returns year
    private:
        int day;
        int month;
        int year;
        int leap_year(); // returns true if year is a leap
        // year. Required in next_day()
};
#endif

****************************

// A test program for the class Date
// IEA February 1997
#include <iostream>
#include "Date.h"
int main()
{
    Date d1, d2(21,8,34);
    int d,m,y;
    // check initialisation is correct
    std::cout << "First date is ";
    d1.print();
    std::cout << std::endl;
    std::cout << "Second date is ";
    d2.print();
    std::cout << std::endl;
    // check accessor functions
    d = d2.get_day();
    m = d2.get_month();
    y = d2.get_year();
    std::cout << std::endl << d << " "
    << m << " "
    << y << std::endl;
    // check next day is correct
    d2.next_day();
    std::cout << "Next day is ";
    d2.print();
    std::cout << std::endl;
    // check setting date by assignment
    // and another check on next day.
    d1 = Date(31,12,1999);
    d1.next_day();
    std::cout << "Day after 31/12/1999 is ";
    d1.print();
    std::cout << std::endl;
    return 0;
}