December 2011 cumulative time zone update for Windows operating systems

Summary

Important This update supersedes and replaces update 2570791, which was released in August 2011. No additional time zone changes were released as hotfixes after update 2570791 was published.

If you have already deployed update 2570791, read the descriptions of the specific time zone changes that are addressed in this article to determine whether you must deploy this update immediately. If systems are not directly affected, you can schedule deployment at the next available opportunity.

We recommend that you deploy the most current Windows cumulative time zone update to guarantee the consistency of the time zone database on all systems.

Important

• Before you apply the update that is described in this article, be aware of potential issues that may affect Microsoft Outlook.
  
  For more information about these issues, view the article in the Microsoft Knowledge Base:
  931667 How to address time zone changes by using the Time Zone Data Update Tool for Microsoft Office Outlook
  

• If you are running Microsoft Exchange Server in an Information Technology (IT) environment, you must take additional measures to guarantee the correct operation of Exchange Server.
  
  For more information about the Exchange daylight saving time (DST) update, view the article in the Microsoft Knowledge Base:
  941018 How to address daylight saving time by using the Exchange Calendar Update Tool
  

• Cumulative time zone updates contain only data that has changed for a specific region or that was added to maintain parity with other operating system versions. Therefore, if a time zone key is deleted, some original values may not be restored after you apply the cumulative zone update.
  
  We do not recommend that you delete any registry keys that are related to time zones. On a computer that has incomplete time zone keys, first restore the time zone keys from a known good backup. Then, apply the update.

More Information

The update that this article describes changes the time zone data to accommodate daylight saving time (DST) changes in several countries.

The update that this article describes is a cumulative update rollup that includes all previous windows time zone changes. For more information about how DST changes may affect other Microsoft products, visit the following Microsoft website:

http://support.microsoft.com/gp/cp_dst

For more information about how daylight saving time changes may affect other Microsoft products, view the following article in the Microsoft Knowledge Base:

914387 How to configure daylight saving time for Microsoft Windows operating systems

Note When you apply this update, you may receive the following message:

Update cannot be installed as a newer or same time zone update has already been installed on the system.

This message indicates that you have already applied the correct update or that Windows Updates or Microsoft Update has automatically installed this update. No additional action is required to update the Windows operating system.

To get the stand-alone package for this update, go to the Microsoft Update Catalog website.

For more information about how to download Microsoft support files, view the following article in the Microsoft Knowledge Base:

119591 How to obtain Microsoft support files from online services



Updates from the previous cumulative Windows time zone update

The following changes were made since the previous Windows cumulative time zone update:

• Kaliningrad Standard Time:
  As previously announced in Microsoft Knowledge Base article 2625508, Belarus has decided to discontinue daylight saving time from 2011 and stay on permanent "summer time." That article suggested that users move to a "workaround time" of Kaliningrad standard time. This windows update makes the move permanent by including Minsk in the display name for Kaliningrad standard time. The new display name for Kaliningrad standard time is "(UTC+03:00) Kaliningrad, Minsk."

• E.Europe Standard Time:
  The display name for this time zone has been updated to "(UTC+2:00) Nicosia."

• Bahia Standard Time [Display Name "(UTC-3:00) Salvador"]:
  A new windows time zone has been created for the Brazilian state of Bahia.

• Fiji Standard Time [Display Name "(UTC+12:00) Fiji"]:
  Sets the 2012 DST start date to occur on the fourth Sunday of January.

• Samoa Standard Time:
  Changes the UTC offset for Samoa standard time from (UTC-11) to (UTC+13). As a result, the time zone’s display name changes to "(UTC+13:00) Samoa."

Note Users in Samoa standard time should not install this update before the upcoming time transition on December 29. This update should be installed only at or after 23:59:59 on December 29, 2011.


Known issues

• After you install this update, the 2011 rule for Samoa will be updated to (UTC+13). This results in incorrect history lookup for the majority of 2011 (until the time transition on December 29, 2011). An update has been issued to resolve this issue: http://support.microsoft.com/kb/2657025.

• For Outlook 2010, after you install this update, certain appointments that occur on Saturdays (including December 31, 2011 and later Saturdays) may disappear from the Calendar view. For information about the issue and workarounds, see http://support.microsoft.com/kb/2655312.  
  
  This issue does not affect Outlook 2003 or Outlook 2007.

Windows XP

Prerequisites

You must have Windows XP Service Pack 3 (SP3) installed to apply this update. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

322389 How to obtain the latest Windows XP service pack


Restart requirement

You may have to restart the computer after you apply this update.


Update replacement information

Note You can install this cumulative update rollup even after you have installed any of the following previously released updates. This update replaces the following update:

2570791 August 2011 cumulative time zone update for Microsoft Windows operating systems


Windows Server 2003

Prerequisites

You must have Windows Server 2003 SP2 installed to apply this update. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

889100 How to obtain the latest service pack for Windows Server 2003

Restart requirement

You may have to restart the computer after you apply this update.

Update replacement information

Note You can install this cumulative update rollup even after you have installed any of the following previously released updates. This update replaces the following update:

2570791 August 2011 cumulative time zone update for Microsoft Windows operating systems


Windows Vista or Windows Server 2008

Prerequisites

You must have Windows Vista or Windows Server 2008 Service Pack 2 installed to apply this update.

Restart requirement

You may have to restart the computer after you apply this update.

Update replacement information

Note You can install this cumulative update rollup even after you have installed any of the following previously released updates. This update replaces the following update:

2570791 August 2011 cumulative time zone update for Microsoft Windows operating systems


Windows 7 or Windows Server 2008 R2

Prerequisites

No prerequisites are required to apply this update. The same package installs both on the RTM version as well as the SP1 versions of Windows 7 and Windows Server 2008 R2.

Restart requirement

You may have to restart the computer after you apply this update.

Update replacement information

Note You can install this cumulative update rollup even after you have installed any of the following previously released updates. This update replaces the following update:

2570791 August 2011 cumulative time zone update for Microsoft Windows operating systems