获得两天之间相差的天数。

	private static int daysBetween(Date date1, Date date2) {Calendar cal = Calendar.getInstance();cal.setTime(date1);long time1 = cal.getTimeInMillis();cal.setTime(date2);long time2 = cal.getTimeInMillis();long between_days = (time2 - time1) / (1000 * 3600 * 24);return Integer.parseInt(String.valueOf(between_days)) + 1;}

在当前日期时间上加一天。

	private static Date getnextDay(final Date date) {Calendar c = Calendar.getInstance();c.setTime(date);c.set(Calendar.DATE, c.get(Calendar.DATE) + 1);c.set(Calendar.HOUR_OF_DAY, 0);c.set(Calendar.MINUTE, 0);c.set(Calendar.SECOND, 0);c.set(Calendar.MILLISECOND, 0);return c.getTime();}

获得指定天数是一周的第几天。

	private int getDayOfWeek(Date date) {Calendar cal = Calendar.getInstance();cal.setTime(date);long whichDay1 = cal.get(Calendar.DAY_OF_WEEK);return Integer.parseInt(String.valueOf(whichDay1)) - 1;}

这个是一周的第几天，与下面的数组对应。

		String[] weeks = new String[] { "星期日", "星期一", "星期二", "星期三", "星期四","星期五", "星期六" };