Meetings are unexpectedly moved one hour ahead in the last week of October in Exchange Server 2003

When you use Collaborative Data Objects (CDO) to create meetings programmatically in Microsoft Exchange Server 2003, meetings are unexpectedly moved one hour ahead in the last week of October.

This problem occurs when all the following conditions are true:

• Users in your organization use e-mail clients such as Microsoft Outlook Web Access. Alternatively, users use other devices or programs that use CDO to view and to manage their calendars.
• Your organization is configured to a time zone that is represented by Coordinated Universal Time (UTC) time 00:00. (Coordinated Universal Time is also known as Greenwich Mean Time [GMT].)
  
  Note This problem does not affect Exchange if the organization is configured to use a time zone other than a time zone in UTC 00:00.
• The month of October has five Sundays.

In a UTC 00:00 time zone, daylight saving time ends on the last Sunday in October. However, a code defect in CDO causes the daylight saving time adjustment to occur on the fourth Sunday in October. This code defect causes an incorrect daylight saving time adjustment to occur in years that have five Sundays in October. For example, for client programs that use CDO to access meeting information, the daylight saving time adjustment occurs on October 22, 2006 instead of October 29, 2006 as expected.

Note This problem will occur next in the year 2010.

Hotfix information

A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.

If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site: Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.

Prerequisites

You must install Microsoft Exchange Server 2003 Service Pack 2 (SP2) before you apply the hotfix.

For more information, click the following article number to view the article in the Microsoft Knowledge Base:

Restart requirement

You do not have to restart your computer after you apply this hotfix. The Microsoft Exchange Information Store Service will be restarted when the fix is applied.

Hotfix replacement information

This hotfix does not replace any other hotfixes.

File information

The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.

Hotfix installation information

You only have to install this hotfix on the servers that are running the CDO application. You do not have to install this hotfix on every Exchange server in the organization.

For more information about applying hotfixes for CDO applications, click the following article number to view the article in the Microsoft Knowledge Base:

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

For more information, click the following article numbers to view the articles in the Microsoft Knowledge Base: