XWEB: Appointments Created with OWA Appear To Be Shifted One Hour Ahead when Viewed with Outlook

If you use Outlook Web Access (OWA) to create appointments that fall in the seven days before the last Sunday in October of any given year, the start and end times may appear to be shifted one hour ahead if you view them by using Microsoft Outlook. For some time zones this may also happen for dates in the seven days before the last Sunday in September. In some cases the appointments are also displayed incorrectly in OWA even though they were created there.

In 1996, the European Union (EU) standardized a EU-wide daylight saving period that starts on the last Sunday in March and ends on the last Sunday in October. Before the standardization, some EU countries implemented a daylight saving time that ended on the last Sunday in September. The Collaboration Data Objects (CDO) libraries didn't implement this change properly.

To resolve this problem, obtain the latest service pack for Exchange Server 5.5. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

Microsoft has confirmed that this is a problem in Microsoft Exchange Server version 5.5. This problem was first corrected in Exchange Server 5.5 Service Pack 4.

To manually install this hotfix you need the Microsoft Register Server program, Regsvr32.exe. The Regsvr32.exe file is usually installed in your Windows\System32 folder. If you cannot locate the Regsvr32.exe file on your computer, you can obtain it from the Microsoft Download Center. For additional information about where to obtain the Regsvr32.exe file, click the article number below to view the article in the Microsoft Knowledge Base: After you obtain the Regsvr32.exe file, you must perform the following steps to install this hotfix:

NOTE: The paths used in the steps, such as C:\Winnt\System32 or C:\Exchsrvr\Bin, may be different on your system, depending on your installation of Microsoft Windows NT Server or Microsoft Exchange Server.

1. Copy the Regsvr32.exe file to your Windows\System32 folder.
2. Stop all of the services that are related to Internet Information Server (IIS).
3. Stop all of the Exchange Server services.
4. Unregister the current Cdo.dll file; at a command prompt, type regsvr32 /u c:\winnt\system32\cdo.dll. A dialog box is displayed that indicates the success of this operation.
5. Unregister the current Cdohtml.dll file; at a command prompt, type regsvr32 /u c:\exchsrvr\bin\cdohtml.dll. A dialog box is displayed that indicates the success of this operation.
6. Copy build 2651.70 of the Cdo.dll file to the C:\Winnt\System32 folder.
7. Copy build 2651.70 of the Cdohtml.dll file to the C:\Exchsrvr\Bin folder.
8. Register the new Cdo.dll file; at a command prompt, type regsvr32 c:\winnt\system32\cdo.dll.
9. Register the new Cdohtml.dll file; at a command prompt, type regsvr32 c:\exchsrvr\bin\cdohtml.dll.
10. Restart all of the IIS-related services.
11. Restart all of the Exchange Server services.
12. For each client that requires OWA to the mailbox calendar, connect to the client mailbox by using OWA, and in the left pane, click Calendar, and then click Options to ensure that the appropriate time zone is configured. Click OK to save configuration changes.