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

public class DateTest {
  public static void main (String [] s) {
    GregorianCalendar calendar = new GregorianCalendar ();
    calendar.set (1999, Calendar.JUNE, 1);
    long initialDate = calendar.getTime().getTime ();
    calendar.setTime (new Date ());
    long finalDate = calendar.getTime().getTime ();

    long period = finalDate - initialDate;

    long periodInDays = ((((period / 1000) / 60) / 60) / 24);

    System.out.println ("Period: " + periodInDays);


  }

  static long fromMillisToDays (long millis) {
    return (((milis / 1000) / 60) / 60) / 24;
  }

}