The government of Chile has extended the 2011 Daylight Saving Time so it ends May 7th. This hotfix updates Windows DST support for (UTC -4:00) Santiago so that DST ends May 7, 2011 at 23:59:59.999 and the clock reverts to 23:00:00.000.
The government of Egypt has decided to cancel Daylight Saving Time. This hotfix updates Windows support for (UTC +2:00) Cairo so it will no longer have DST support.
The government of Morocco has changed the 2011 Daylight Saving Time schedule to end July 30th at midnight. This hotfix updates Windows DST support for (UTC) Casablanca so 2011 DST ends July 30, 2011 at 23:59:59.999 and the clock reverts to 23:00:00.000.
You can request the update by visiting KB 2543367 or directly here, once you are in the hotfix request site make sure to select the option "Show hotfixes for all platforms and languages" to view the complete list of languages and operating systems.
Note: Windows 2008 and Windows Vista update packages are built from the same servicing branch and are shown under the Vista Product name on the download page. The Vista titled package does install and update on Windows 2008.
For more information see Microsoft Knowledge Base: 2543367 Hotfix available for Windows Daylight Saving Time Support for Chile, Egypt, and Morocco.