class Date{
    private int day;
    private int month;
    private int year;
    public Date(int d,int m,int y){
        day = d;
        month = m;
        year = y;
    }
    public int getDay(){
        return day;
    }
    public int getMonth(){
        return month;
    }
    public int year(){
        return year;
    }
    public void display(){
        System.out.println("Today is "+year+","+month+","+day);
    }
    public void succussorDate(){
        int daysInMonth[]={31,28,31,30,31,30,31,31,30,31,30,31};
        if(year%4==0&&(year%100!=0||year%400==0))
          daysInMonth[1]=29;
        if(day<daysInMonth[month])
          day++;
        else{
            day=1;
            if(month<12)
              month++;
            else{
                month=1;year++;
            }
        }
    }
    public boolean equals(){
        
    }
}
这个successordate方法是什么意思呢？