我想计算不同时区内日期之间的时差。我将这两次转换为格林威治时间。但是当我在Europe/Moscow
时区转换日期时,偏移量是不同的,尽管没有夏令时。
这是我检查过的情况:
SELECT TO_DATE('5/20/2018 10:05:00 PM','mm/dd/yyyy hh:mi:ss am'),
TO_DATE('5/20/2018 10:05:00 PM','mm/dd/yyyy hh:mi:ss am')
- extract(TIMEZONE_HOUR from from_tz (TO_TIMESTAMP('5/20/2018 10:05:00 PM','mm/dd/yyyy hh:mi:ss am') ,'GMT' ) at time zone 'Europe/Moscow')/24 deptime_GRINICH
from dual
UNION
SELECT TO_DATE('5/24/2018 11:35:00 PM','mm/dd/yyyy hh:mi:ss am'),
TO_DATE('5/24/2018 11:35:00 PM','mm/dd/yyyy hh:mi:ss am')
- extract(TIMEZONE_HOUR from from_tz (TO_TIMESTAMP('5/24/2018 11:35:00 PM','mm/dd/yyyy hh:mi:ss am') ,'GMT' ) at time zone 'Europe/Moscow')/24 deptime_GRINICH
from dual
结果是:
Date date converting to Greenwich time zone
5/20/2018 10:05:00 PM 5/20/2018 6:05:00 PM --> hour difference 4 hours
5/24/2018 7:35:00 PM 5/24/2018 3:35:00 PM --> hour difference 4 hours
但2018年时区 - 索契是UTC + 3h
答案 0 :(得分:1)
2014年10月,俄罗斯改变了日光节约的规则。 Oracle数据库中的时区文件可能是旧文件,但不包含最近的更改。使用
验证版本SELECT * FROM V$TIMEZONE_FILE;
并考虑升级,请参阅Upgrading the Time Zone File and Timestamp with Time Zone Data
但是,它似乎是Oracle中的一个错误。看看我的查询比你的例子更明确:
SELECT *
FROM NLS_SESSION_PARAMETERS
WHERE parameter LIKE 'NLS_TIMESTAMP_TZ_FORMAT';
PARAMETER VALUE
-------------------------- --------------------------------------
NLS_TIMESTAMP_TZ_FORMAT YYYY-MM-DD HH24:MI:SSfmXFF3 fmTZH:TZM
1 row selected.
SELECT
EXTRACT(TIMEZONE_HOUR FROM TIMESTAMP '2018-05-20 22:05:00 Europe/Moscow') AS TZ_HOUR,
TO_CHAR(TIMESTAMP '2018-05-20 22:05:00 Europe/Moscow', 'YYYY-MM-DD HH24:MI:SS TZH:TZM') AS ts2,
TIMESTAMP '2018-05-20 22:05:00 Europe/Moscow' AS ts3
FROM dual;
TZ_HOUR TS2 TS3
---------- ------------------------------ ----------------------------------
4 2018-05-20 22:05:00 +04:00 20.05.2018 22:05:00.000000000 +03:00
1 row selected.
这真的很奇怪,因为TZH:TZM
,分别是。 EXTRACT(TIMEZONE_HOUR FROM ...)
返回的值与默认NLS_TIMESTAMP_TZ_FORMAT = ... TZH:TZM
不同。对于其他时区(例如Europe/Zurich
),我始终02:00
- 正如预期的那样。
您可以在Oracle支持部门打开一张票。
我有两个数据库,旧数据库和新数据库。旧的并没有反映俄罗斯夏令时的最近变化,而新的变化则是如此。但是,上述错误同时出现在:
ALTER SESSION SET NLS_TIMESTAMP_TZ_FORMAT = 'YYYY-MM-DD HH24:MI:SS TZH:TZM';
SELECT filename, VERSION,
TO_CHAR(TIMESTAMP '2018-05-20 22:05:00 Europe/Moscow', 'TZH:TZM TZD') AS ts1,
TIMESTAMP '2018-05-20 22:05:00 Europe/Moscow' AS ts2,
TO_CHAR(TIMESTAMP '2018-01-20 22:05:00 Europe/Moscow', 'TZH:TZM TZD') AS ts3,
TIMESTAMP '2018-01-20 22:05:00 Europe/Moscow' AS ts4
FROM V$TIMEZONE_FILE;
Old (Daylight-Saving times still existing due to old timezlrg_14.dat file):
FILENAME VERSION TS1 TS2 TS3 TS4
---------------- -------- ----------- ------------------------------------ ----------- -------------------------------------
timezlrg_14.dat 14 +04:00 MSD 20.05.2018 22:05:00.000000000 +03:00 +03:00 MSK 20.01.2018 22:05:00.000000000 +03:00
New (no Daylight-Saving time changes):
FILENAME VERSION TS1 TS2 TS3 TS4
---------------- -------- ----------- ------------------------------------ ----------- -------------------------------------
timezlrg_18.dat 18 +04:00 MSK 20.05.2018 22:05:00.000000000 +03:00 +04:00 MSK 20.01.2018 22:05:00.000000000 +03:00