获取本月月末到12个月之前的时间（中间相隔12个月）

	SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    Calendar cale = Calendar.getInstance();
	cale.set(Calendar.HOUR_OF_DAY, 0);
    cale.set(Calendar.MINUTE, 0);
    cale.set(Calendar.SECOND, 0);
    cale.add(Calendar.MONTH, 1);
    cale.set(Calendar.DAY_OF_MONTH, 0);
    String lastday = format.format(cale.getTime());
    Calendar cale1 = Calendar.getInstance();
    cale1.set(Calendar.HOUR_OF_DAY, 0);
    cale1.set(Calendar.MINUTE, 0);
    cale1.add(Calendar.MONTH, 1);
    cale1.add(Calendar.YEAR, -1);
    cale1.add(Calendar.MONTH, 0);
    cale1.set(Calendar.DAY_OF_MONTH, 1);
    cale1.set(Calendar.SECOND, 0);
    String firstday = format.format(cale1.getTime());
    System.out.println("一年前的月份第一天是" +  firstday);
    System.out.println("一年后的月份最后一天是" + lastday);

执行结果：

一年前的月份第一天是2018-05-01 00:00:00
一年后的月份最后一天是2019-04-30 00:00:00

正好相隔一年，记录以备以后查看。