At the start of 2007, Microsoft released an update (KB 931836) to update the Time Zone rules on Windows Operating Systems.  On November 4, 2007 Daylight Saving Time (DST) will end in the United States.  However, other parts of the world observe different DST rules.  Since the release of the hotfix in February, various time zone changes have been signed into law around the world.

Microsoft has released a new Cumulative Time Zone update for the Windows Operating Systems, outlined in KB 933360.  The following changes have been made since KB 931836 was released:

  • Caucasus Standard Time: Changes the display name to Caucasus Standard Time as cities in the previous display name have separate time zones, and removes DST settings.
  • Armenian Standard Time: Creates a new time zone for Armenia to better align with different DST changes in the Caucasus region
  • New Zealand Standard Time: Adjusts DST start and end dates according to changes signed into law after the prior cumulative time zone update was released
  • GTB Standard Time: Corrects the display name for GTB Standard Time on Windows Server 2003 SP2 to include Bucharest
  • Jordan Standard Time: Adjusts DST start times, end times, and dates according to changes signed into law after the prior cumulative time zone update was released

The majority of customers who contact us regarding the DST changes are mostly concerned with how to ensure that their Windows clients and Outlook / Exchange clients are correctly updated.  Below is the general order of updating for DST changes:

Patching Order for Windows, Exchange and Outlook Clients

  1. Apply the updates to Windows Operating Systems on Windows Servers
  2. Apply the updates to Windows Operating Systems on individual workstations
  3. Run the Exchange Calendar Update Tool against all affected users, servers, or both OR correct the individual e-mail application calendars using the Outlook Time Zone Data Update Tool
  4. Apply the Exchange Server DST Update

With respect to KB 933360, there is a known issue when you install this update on a computer that is running Windows Server 2003 with Service Pack 1, and you then install Windows Server 2003 Service Pack 2.  Bucharest no longer appears in the display name of the GTB time zone.  GTB Standard Time appears as "(GMT +02:00) Athens, Beirut, Istanbul, Minsk" instead of as "(GMT +02:00) Athens, Bucharest, Istanbul."  This issue will be corrected in a future update.  To work around this issue, you can use the Time Zone Editor (Tzedit.exe) to modify the display name. Alternatively, you can use the TZChange utility to modify the time from the command prompt:

%systemroot%\system32\tzchange.exe /F"GTB Standard Time" /N"(GMT+02:00) Athens, Bucharest, Istanbul"

As always, please test any changes in a controlled environment before deployment to production.  That's it for this post - the main Microsoft resources for DST are listed below.  Until next time ...

Additional Resources:

- CC Hameed