common_helper/src/main/java/com/xiongyingqi/util/DateHelper.java
public static Date getNextDay(Date nowDate, int delay) {
        long myTime = (nowDate.getTime() / 1000) + delay * 24 * 60 * 60;
        Date date = new Date();
        date.setTime(myTime * 1000);
        return date;
    }
public static Date getNextDay(Date nowDate, int delay) {
        long myTime = (nowDate.getTime() / 1000) + delay * 24 * 60 * 60;
        Date date = new Date();
        date.setTime(myTime * 1000);
        return date;
    }
得到一个时间延后或前移几天的时间,nowdate为时间,delay为前移或后延的天数