java.util.Date类型日期增减的方法

public static void main(String[] args) {
    Calendar c = Calendar.getInstance();
    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
    c.set(Calendar.YEAR, 2013);
    c.set(Calendar.MONTH, 1);
    c.set(Calendar.DATE, 3);
    //默认当月与当月距离为1，相邻两个月距离为2，故减-2
    c.add(Calendar.MONTH, -2);
    System.out.println(sdf.format(c.getTime()));
}