Outlook Time Zone Data Update Tool 2.0 and earlier versions of this tool do not correctly rebase any calendar item that was created in the Brasilia time zone

Microsoft Office Outlook Time Zone Data Update Tool 2.0 and earlier versions of this tool do not correctly rebase any calendar item that was created in the Brasilia time zone.

Because of limitations in Outlook Time Zone Data Update Tool 2.0 and earlier versions, rebasing for the Brasilia time zone is not supported. This issue occurs because Outlook Time Zone Data Update Tool 2.0 and earlier versions do not support time zone definitions that change partway through a particular year.

Outlook Time Zone Data Update Tool 3.0 partly addresses this issue. In Outlook Time Zone Data Update Tool 3.0, all calendar items that have time zone properties stamped on them are rebased correctly. However, items that do not have time zone properties stamped on them may be rebased incorrectly. By using the appropriate command line argument, you can disable unstamped items.

For more information, click the following article number to view the article in the Microsoft Knowledge Base: Before you decide to use Outlook Time Zone Data Update Tool 3.0, you should consider, case by case, how effective the tool may be for your environment. If you decide to run this tool on your calendar, visit your calendar after you run the tool, and then review the calendar items to make sure that the items appear at the correct times.

Some versions of Microsoft Outlook, of Outlook Mobile, of Outlook Web Access, of Microsoft Office SharePoint Server, and of Windows SharePoint Services do not stamp time zone properties on some calendar item types. Without this data, Outlook Time Zone Data Update Tool 3.0 is likely to rebase calendar items incorrectly for time zones where the time zone definitions have changed partway through a particular year, such as in the Brasilia time zone. Therefore, you should pay particular attention before you run the tool.

For the Brasilia time zone, Outlook Time Zone Data Update Tool 3.0 correctly detects and rebases all items that have a time zone definition stamped on them. These include the following:

• All items that were created by using Office Outlook 2003 Service Pack 3 (SP3) or later versions
• Recurring items that were created by using any version of Office Outlook or any version of Outlook Web Access
• Recurring items that were created by using Outlook Mobile
• Single instance items that were created by using iCalendar (iCal) or Outlook Web Access for Exchange Server 2007

For the Brasilia time zone, this tool might incorrectly rebase any item that does not have a time zone definition stamped on it. These include the following:

• Single instance items that were created by using Office Outlook 2003 Service Pack 2 (SP2) and earlier versions
• Single instance items that were created by using Outlook Mobile, Outlook Web Access for Exchange Server 2003, Office SharePoint Server, and Windows SharePoint Services