code: public static Calendar getDateCeil(Date date) {
          Calendar cal = new GregorianCalendar();
          cal.setTime(date);
          return new GregorianCalendar(cal.get(Calendar.YEAR), cal.get(Calendar.MONTH), cal.get(Calendar.DAY_OF_MONTH));
      }
docs: 获取指定日期的0时 如输入2008-11-13 16:00，则输出2008-11-13 00:00