Microsoft has learned of a possible change in the observance of daylight saving time in Iraq that could affect customers who use the “(GMT +03:00) Baghdad” time zone. (This is also known as the Arabic time zone.) We have unofficial reports that the Ministry of Iraq has decided that the country will no longer observe daylight saving time. Daylight saving time has historically taken effect in Iraq on April 1 and has continued through October 1. Currently, it seems that this change is likely. However, this information could be reversed at any time.

On April 1, 2008, Windows-based computers that are configured to use the “(GMT +03:00) Baghdad” time zone will automatically transition to daylight saving time despite the expected change in Iraq’s daylight saving time policy. However, the hotfix that is described in the “More information” section updates the “(GMT +03:00) Baghdad” time zone in compliance with this expected policy change, beginning April 1, 2008.

For more information about time zone changes in Windows, click the following article number to view the article in the Microsoft Knowledge Base:

942763 December 2007 cumulative time zone update for Microsoft Windows operating systems

The update that this article describes changes the time zone data to account for daylight saving time (DST) changes in several countries, as outlined. This update also includes other DST-related changes, time zone-related changes, and settings-related changes. Some of these changes will occur in 2007. Some of these changes have occurred since the products that are listed in the “Applies to” section were originally released. The update that this article describes is a cumulative update rollup that includes all the changes that were previously released in Microsoft Knowledge Base (KB) article 928388 and in KB article 929120. This update also describes some additional changes that have occurred since the last cumulative update in KB article 928388 and in KB article 931836.

You use a Windows Vista-based computer that supports High Precision Event Timer (HPET), and the computer runs for several hours. Then, you may notice that the system time differs from the BIOS time by several seconds.

On a computer that is running Windows Vista, you perform an editing operation or a playback operation on a MIDI audio device. When you do this, you may notice timing jitter and clock drift.

This problem occurs if the following conditions are true:

• The MIDI device does not reside on the peripheral component interconnect (PCI) bus.
• The MIDI device does not advertise any audio endpoints.

Consider the following scenario:

• You have a Windows Vista-based computer that has the Croatian Language Pack installed.
• You select a time zone such as Sarajevo in the Date and Time dialog box.

In this scenario, the wrong time zone may be applied.

When you use the Microsoft .NET Framework 2.0 in Windows Vista, the DateTime.Now property may display results that are incorrect by one hour. This problem occurs if the following conditions are true:

• Windows Vista is configured to use the Jerusalem time zone.
• The months contain daylight saving time (DST) transitions.

For example, in 2007, the DateTime.Now property incorrectly reports DST as starting five days early (on March 25 instead of on March 30). Additionally, the DateTime.Now property will incorrectly report DST as ending 14 days late (on September 30 instead of on September 16).

Therefore, .NET Framework programs such as Windows Media Center that are running in Windows Vista will be off by one hour in the Jerusalem time zone during these periods.

On a computer that is running Windows Vista, a 6.6.x.x version of the Cdosys.dll file is installed. On this computer, you apply the daylight saving time (DST) updates that are described in the following Microsoft Knowledge Base article:

933360 August 2007 cumulative time zone update for Microsoft Windows operating systems

After you apply these updates, applications that use Collaboration Data Objects (CDO) process the current time in the old version of the local time zone instead of in the updated version of the local time zone. Therefore, the applications may display the incorrect time.

For example, you may expect an e-mail message to have the following time stamp when you send it at 9:37 P.M. on March 11, 2007:

11 March 2007 21:37 (GMT-7)

However, the message displays the following time stamp:

11 March 2007 20:37 (GMT-7)

Consider the following scenario. In a domain that uses the Active Directory directory service, you grant the “Change the time zone” user right to some users or to some groups. Then, you use Group Policy Management Console (GPMC) to generate a Group Policy Results report on a client computer that is running Windows Vista.

In this scenario, when you view the Group Policy Results report, the “Change the time zone” policy setting is absent.

Note: The “Change the time zone” policy setting is in the following location:

Computer Configuration\Windows Settings\Security Settings\Local Policies\User Rights Assignment

Consider the following scenario. You have a domain on which user accounts reside and another domain on which computer accounts reside. You have established a trust relationship between these domains. However, when you try to log on to a Windows Vista-based client computer across the trust, the logon process fails. Additionally, you receive an error message that contains a white “X� inside a red circle. The text of this error message resembles the following:

There is a time and/or date difference between the client and server.

Note: This issue occurs even though there is no significant time difference between the client computer and the server. This issue occurs only on Windows Vista-based client computers.

You have a Windows Vista-based computer that supports High Precision Event Timer (HPET). When you restart the computer, the system time that is displayed on the clock lags behind the actual time. After you restart the computer several times, the system time lags behind the actual time even more.