MySQL Bugs: #66681: Timezone support on Windows

Bug #66681	Timezone support on Windows
Submitted:	4 Sep 2012 12:31	Modified:	5 Sep 2012 20:16
Reporter:	Peter Laursen (Basic Quality Contributor)	Email Updates:
Status:	Duplicate	Impact on me:	None
Category:	MySQL Server: Installing	Severity:	S3 (Non-critical)
Version:	any	OS:	Windows
Assigned to:		CPU Architecture:	Any

Description:
http://dev.mysql.com/downloads/timezones.html
http://dev.mysql.com/doc/refman/5.5/en/mysql-tzinfo-to-sql.html

and inspired by this other bug report http://bugs.mysql.com/bug.php?id=66678.

The timezome name on my Windows 7 (Danish) system is 'Rom, sommertid' - not 'Europe/Rome' as shipped with the donload package in 1st link above

How to repeat:
I have downloaded and installed the package from first link.

SELECT * FROM `mysql`.`time_zone_name` WHERE `name` LIKE '%rom%'
/*
Name         Time_zone_id  
-----------  --------------
Europe/Rome             449
*/

-- query
SELECT 
 @@global.time_zone, 
 @@global.system_time_zone, 
 CONVERT_TZ(NOW(),@@global.time_zone, 'US/Central'),  
 CONVERT_TZ(NOW(),'Rom, sommertid', 'US/Central');
 
/* result
 SYSTEM              
 Rom, sommertid             
 2012-09-04 07:11:22                                 
 (NULL)   -- < note this
*/

-- But

SELECT 
 @@global.time_zone, 
 @@global.system_time_zone, 
 CONVERT_TZ(NOW(),@@global.time_zone, 'US/Central'),  
 CONVERT_TZ(NOW(),'Europe/Rome', 'US/Central');
-- works as expected - no NULL in result.

Suggested fix:
Provide timezone names supported on Windows or document how to generate them from Windows. Neither links above has any hint for Windows users.

(I don't find this a duplicate of the other bug but you can change that if you think it is better)

Thank you for the report.

This is not Windows issue. Look at the output from my Linux machine:

mysql> SELECT   @@global.time_zone,   @@global.system_time_zone;+--------------------+---------------------------+
| @@global.time_zone | @@global.system_time_zone |
+--------------------+---------------------------+
| SYSTEM             | EEST                      |
+--------------------+---------------------------+
1 row in set (0.00 sec)

mysql> select * from mysql.time_zone_name where name like '%EEST%';
Empty set (0.00 sec)

This is issue of how OS timezones stored. Please also note select CONVERT_TZ(NOW(),'SYSTEM', 'US/Central'); perfectly works and returns correct results.

So this can be either "Not a Bug" or documentation request.

Reporter of bug #66678 complains, so I verified it as documentation bug and set this as duplicate: they are really about same thing.