I have a simple task. There are two classes : Ticket and Date. Ticket contains event, event place and event date which is a Date object. I also need to provide a move() method for Date object, so I used Calendar and Calendar's add(). Everything looks fine apart of the output. I constantly get 5,2,1 as the date's day,month,year. Lines with asterix return proper date.

The code :

Ticket class :

public class Ticket {

private String what;
private String where;
private Date when;

public Ticket(String s1, String s2, Data d){
    this.what = s1;
    this.where = s2;
    this.when = d;
}

*public Date giveDate(){
    System.out.println("when in giveDate() "+this.when);
    return this.when;
}

public String toString(){
    return "what: "+this.what+"\n"+"where: "+this.where+"\n"+"when: "+this.when;
}

}

Date class:

import java.util.Calendar;
import java.util.GregorianCalendar;

public class Date {

public int day;
public int month;
public int year;

public Date(int x, int y, int z){
    *System.out.println("x: "+x);
    *System.out.println("y: "+y);
    *System.out.println("z: "+z);

    this.day = x;
    this.month = y;
    this.year = z;

    *System.out.println("this.day: "+this.day);
    *System.out.println("this.month: "+this.month);
    *System.out.println("this.year: "+this.year);
}

public Date move(int p){

    *System.out.println("before_change: "+this.day+","+this.month+","+this.year);

    Calendar gc = new GregorianCalendar(this.year, this.month, this.day);
     System.out.println("before_adding: "+gc.DAY_OF_MONTH+","+gc.MONTH+","+gc.YEAR);
    gc.add(Calendar.DAY_OF_YEAR, p);

    System.out.println("after_adding: "+gc.DAY_OF_MONTH+","+gc.MONTH+","+gc.YEAR);

    this.year = gc.YEAR;
    this.day = gc.DAY_OF_MONTH;
    this.month = gc.MONTH;

    return this;
}

@Override
public String toString(){
    return this.day+","+this.month+","+this.year;
}

}

Main for testing :

public class Main {

public static void main(String[] args) {

     Date date1=new Date(30,4,2002);
     Ticket event1=new Ticket("Peter Gabriel's gig",
                              "London",date1
                             );

     Ticket event2=new Ticket("Diana Kroll's concert",
                              "Glasgow",date1
                             );

     Date date2=event2.giveDate();

     date2.move(30);
     Ticket event3=new Ticket("X's B-day",
                              "some place",date2
                             );

     System.out.println(date1);
     System.out.println(event1);
     System.out.println(event2);
     System.out.println(event3);
}

}

And here's my output. I just can't get it where 5,2,1 come from :/

x: 30
y: 4
z: 2002
this.day: 30
this.month: 4
this.year: 2002
when in giveDate() 6,12,2004
before_change: 6,12,2004
before_adding: 5,2,1
after_adding: 5,2,1
5,2,1
what: Peter Gabriel's gig
where: London
when: 5,2,1
(...)