DateTest

class Date {
	private int month;
	private int day;
	private int year;
	
    public Date(int month, int day, int year) {
		this.month = checkMonth(month);
		this.year = year;
		this.day = checkDay(day);
	}
	private int checkMonth(int testMonth) {
		if (testMonth >= 1 && testMonth <= 12)
			return testMonth;
		else
			return 1;
	}
	private int checkDay(int testDay) {
		int[] daysPerMonth = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
		if (testDay > 0 && testDay <= daysPerMonth[month])
			return testDay;
		if (month == 2 && testDay == 29 && (year % 400 == 0 || (year % 4 == 0 && year % 100 != 0)))
			return testDay;
		return 1;
	}
	public void increase() {
	day++;
	int[] daysPerMonth = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
	if (day > daysPerMonth[month]) {
		day = 1;
		month++;
	if (month > 12) {
		month = 1;
		year++;
	}
	if (month == 2 && day == 29 && (year % 400 == 0 || (year % 4 == 0 && year % 100 != 0))) {
		day = 29;
		}
	}
}
	public String toString() {
		return month + "/" + day + "/" + year;
		}
	}
public class DateTest {
	public static void main(String[] args) {
		Date date1 = new Date(3, 1, 2018);
		Date date2 = new Date(1, 1, 2020);
	
    	System.out.println("Entrance date: " + date1);
		System.out.println("date2: " + date2);
		for(int i=0; i<700; i++) {
			date2.increase();
			System.out.println(date2);
		}
	}
}