MySQL Bugs: #70436: Incorrect mapping of windows timezone to Olson timezone

Bug #70436	Incorrect mapping of windows timezone to Olson timezone
Submitted:	26 Sep 2013 13:22	Modified:	12 Sep 2014 17:15
Reporter:	Alexander Nalbandyan	Email Updates:
Status:	Closed	Impact on me:	None
Category:	Connector / J	Severity:	S2 (Serious)
Version:	5.1.26	OS:	Windows (7 x64/x86)
Assigned to:	Filipe Silva	CPU Architecture:	Any

Description:
Mysql jdbc driver maps windows timezone to oslon timezone incorrectly for following windows timezones.

Current Mapping in JDBC driver:

"Caucasus Standard Time" --> "Asia/Tbilisi"
"Georgian Standard Time" --> no mapping

Mapping according to Cldr Standard(Release 1.8 till 24):

"Caucasus Standard Time" --> "Asia/Yerevan"
"Georgian Standard Time" --> "Asia/Tbilisi"

How to repeat:
To reproduce this but set system timezone on windows to "Yerevan".
And server_time_zone in mysql should be "SYSTEM".

Use Jdbc connection property "useLegacyDatetimeCode=false".

Try loading jdbc driver then ConnectionImpl.configuretimezone method 

this.serverVariables.get("system_time_zone");// "Caucasus Standard Time" (Correct)

but  TimeUtil.getCanoncialTimezone(); //Returns "Asia/Tbilisi" Incorrect.

Also I would like to mention that in case of Tbilisi system timezone in Windows you get exception as there is no mapping.

Suggested fix:
Mappings should be fixed according to cldr Standard

"Caucasus Standard Time" --> "Asia/Yerevan"
"Georgian Standard Time" --> "Asia/Tbilisi"

Here is a link to cldr standard for windows timezone mapping.
http://unicode.org/cldr/trac/browser/tags/release-1-8/common/supplemental/windowsZones.xml

Hi Alexander,

Thank you for this bug report. Verified by code review.

Added the following entry to the Connector/J 5.1.33 changelog:

"Errors occur when Connector/J mapped Windows time zones to Olson time zones for “Caucasus Standard Time” and “Georgian Standard Time”. This fix corrected and updated all the time-zone mappings in Connector/J using the data from the IANA Time Database and the Unicode Common Locale Data Repository (CLDR) v.24."

Corrected the changelog entry to the following:

Errors occur when Connector/J mapped Windows time zones to Olson time zones for “Caucasus Standard Time” and “Georgian Standard Time”. This fix corrected and updated all the time-zone mappings in Connector/J using the data from the IANA Time Database v.2014g and the Unicode Common Locale Data Repository (CLDR) v.25.