Advisory: DST cancellations in Belarus, Ukraine and Armenia

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: support.microsoft.com/kb/2625508