If you have end-users in Russia, or that visit the country frequently to do business, you might not be aware of a country-wide policy to alter the official time zone.
In 2010, Russia reduced its time zones from 11 to nine for economic reasons, but is now prepared to alter them once again. The change will take effect on October 26, 2014 and after this date Windows users will show incorrect time zone data unless a patch is applied.
You can read more about it, and get links to the Windows version-specific downloads here: A September, 2014 time zone update for Russia is available
The update is required for Windows Server 2008 and R2, Windows 7, Windows 8.x, and Windows Server 2012 and R2. Note that the update is not available for users of Windows XP, which may cause some issue for Russian-based computers.