做了個小測試：

create table VIPR_AIRPORT_RULE1
(
  AIRLINE           VARCHAR2(2) not null,
  AIRPORT         VARCHAR2(3) not null,
  START_TIME   DATE not null,
  END_TIME       DATE not null,
  NUM                 NUMBER not null
)

嘗試插入資料：

insert into VIPR_AIRPORT_RULE1 values('CA','PEK',to_date('0000','HH24MI'),to_date('0200','HH24MI'),300);

成功，但查詢時：

SQL> select * from vipr_airport_rule1;
 
AIRLINE AIRPORT START_TIME  END_TIME           NUM
----------- -------------- ------------------- ------------------------ ----------
CA         PEK           2012/9/1          2012/9/1 2:            300

會發現還是存入了年日月，所以只能儲存這種形式。但查詢時可只獲取時間（小時分秒數）：

SQL> select to_char(end_time,'HH24MISS') from vipr_airport_rule1;
 
TO_CHAR(END_TIME,'HH24MISS')
----------------------------
020000