Previous cumulative time zone updates for Windows introduced a discrepancy in the 2011 calendar history of the following time zones:
Samoa Standard Time
Russian Standard Time
Ekaterinburg Standard Time
N. Central Asia Standard Time
North Asia Standard Time
North Asia East Standard Time
Yakutsk Standard Time
Vladivostok Standard Time
Magadan Standard Time
Kaliningrad Standard Time
This update fixes 2011 calendar history for these time zones.
Samoa Time zone changes were included in Microsoft Knowledge Base article 2633952 (December 2011 Cumulative time zone update). As a result of this update, the entire 2011 calendar was updated to (UTC+13). This update reverts the 2011 calendar to (UTC-11) while the 2012 and future calendars will continue to be (UTC+13).
Russian Time zone changes were included in Knowledge Base article 2570791 (August 2011 Cumulative time zone update). As a result of Russia canceling DST and staying on permanent "summer time," the entire 2011 calendar was updated to summer time. This update changes the 2011 calendar to show winter time before March 27, 2011 while DST was still in effect.
Important This update exposes a bug in the "Date and Time" Control Panel item in Windows 7 and Windows Server 2008 R2 that might prevent changing the date and time value within certain ranges. To resolve this problem, please make sure that you have downloaded update KB2657025 and that you have installed it on the system.
For more information about how DST changes may affect other Microsoft products, visit the following Microsoft website:
Windows 7 Service Pack 1, Windows Server 2008 R2 Service Pack 1, Windows Server 2008 Service Pack 2, Windows Vista Service Pack 2, Microsoft Windows XP Service Pack 3, Microsoft Windows Server 2003 Service Pack 2