Very simple dumb implementation of MyCalendar

MyCalendar.java

public class MyCalendar {
    public static DAY = 1;
    public static MONTH = 2;
    public static YEAR = 3;

    private int day;
    private int month;
    private int year;

    public MyCalendar() {
        day = 1;
        month = 0;
        year = 1980;
    }

    public void add(int field, int amount) {
         if(field == DAY) day += amount;
         else if(field == MONTH) month += amount;
         else if(field == YEAR) year += amount;
    }

    public void set(int field, int amount) {
         if(field == DAY) day = amount;
         else if(field == MONTH) month = amount;
         else if(field == YEAR) year = amount;
    }
   
    public int get(int field) {
         if(field == DAY) return day;
         else if(field == MONTH) return month;
         else if(field == YEAR) return year;
         throw new RuntimeException("What are you talking about?");
    }

}

Test.java

public class Test {
    public static void main(String args[]) {
        MyCalendar dumbCalendar = new MyCalendar();
        dumbCalendar.set(MyCalendar.DAY, 1);
        dumbCalendar.set(MyCalendar.MONTH, 1);
        dumbCalendar.set(MyCalendar.YEAR, 2015);

        System.out.println("Some random date " + dumbCalendar.get(MyCalendar.DAY) + dumbCalendar.get(MyCalendar.MONTH) + dumbCalendar.get(MyCalendar.YEAR));

    }
}