Ukraine, Belarus, and Armenia have decided to discontinue daylight saving time starting from 2011. These countries are mirroring Russia's changes by staying on "summer time" indefinitely and not falling back to "winter time" on October 30th 2011.
Microsoft’s guidance to customers in the affected timezones is to move to another windows time zone (referred to as ‘workaround timezone’ in table below). Customers will stay on this workaround time zone until the native timezones are updated in the upcoming cumulative windows time update in December 2011.

No hotfix will be issued in the interim for these changes.

Current New

Impacted Country

Native Timezone

Standard Time

Daylight Time

Workaround Timezone (No DST)

Belarus

(UTC+02:00) Minsk

UTC+2:00

UTC+3:00

(UTC +3:00) Kaliningrad

Ukraine

(UTC+02:00) Helsinki, Kyiv, Riga, Sofia, Tallinn, Vilnius

UTC+2:00

UTC+3:00

(UTC +3:00) Kaliningrad

Armenia

(UTC+04:00) Yerevan

UTC+4:00

UTC+5:00

(UTC+05:00) Tashkent

 


Note: The “(UTC+3:00) Kaliningrad” timezone was introduced in the August 2011 Cumulative Update (KB2570791).
It is therefore a pre-requisite for the above mapping.
 


For more information, refer to this Microsoft KnowledgeBase article: http://support.microsoft.com/kb/2625508