As noted at http://www.afrol.com/articles/29955 on July 23, 2008 and in L'Express newspaper, the government of Mauritius has decided to adopt Summer Time (as it's known in Europe, aka daylight saving time) in the island nation of over 1 million. According to published government announcements, the country will begin recognizing Summer Time in October of this year. Official reports note that DST will begin on October 26, 2008 and end on March 27, 2009.
The steps provided in this bulletin were created to mitigate the impacts that the daylight saving time implementation for customers in Mauritius. These are the impacts primarily anticipated at the time this document was written, and the effects that customers may face are not restricted to them.
The suggested actions on this bulletin may require additional testing. Therefore, if you are not severely affected by the DST changes in Mauritius by using the workaround above, we recommend that you wait for the next DST cumulative update that will likely contain the updates for Mauritius.
Note: The information below in this bulletin contains information about how to modify the registry. Make sure that you back up the registry before you modify it. Make sure that you know how to restore the registry if a problem occurs.
The information described in this document may change without notice. In addition, customers should be aware that further guidance may be provided at any time by Microsoft.
The government of Mauritius announced the implementation of daylight saving time (DST) in Mauritius. The following are the start and end dates for the daylight saving time defined:
Currently, computers in Mauritius use the “(GMT+04:00) 'Abu Dhabi, Muscat” time zone setting. However, the default values for the “(GMT+04:00) 'Abu Dhabi, Muscat” time zone setting in Microsoft Windows are set and do not reflect any daylight saving time start and end dates defined by the government.
This bulletin summarizes the actions recommended for customers in Mauritius to address the implementation of daylight saving time and mitigate its impacts.
Customers may select to follow the guidance below for manually changing the registry on Windows XP and Windows Server 2003. (See the section below for considerations of these changes) Other customers may wish to manually move their own users and systems to another time zone that matches the new daylight saving time rules, such as the Ekaterinburg time zone (GMT+5:00) on Oct 26, 2008 after 3:00 AM. Subsequently, on March 29, 2009 at 2:00 AM, change back to the 'Abu Dhabi, Muscat' time zone (GMT+4:00).
In addition to Microsoft products, other software, OS releases and hardware (phones, routers, switches and managed devices) may require updates/ changes. Appointments that were created in a Microsoft Outlook Calendar before the time zone change will need to be adjusted for the new daylight saving time rules. The following steps will need to be taken to update appointments using the Outlook Time Zone Data Update Tool (see the section titled “Impact for Outlook clients in Mauritius” for Outlook Time Zone Data Update Tool usage information).
This session is based on the following Knowledge Base article:
914387 - How to configure daylight saving time for Microsoft Windows operating systems
One option for Windows XP and 2003 is to create a new time zone to reflect the DST dates defined by the Mauritius government. To do so, please proceed as follows:
1. Create a registry file that will contain a new time zone for Mauritius, following these steps:
1.1. Click Start, click Run, type notepad, and then click OK.
1.2. Copy the following registry information, and then paste it into the Notepad document:
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones\Mauritius Standard Time]
"Std"="Mauritius Standard Time"
"Dlt"="Mauritius Daylight Time"
"Display"="(GMT+04:00) Port Louis"
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones\Mauritius Standard Time\Dynamic DST]
1.3. On the File menu, click Save As.
1.4. Select a destination, and then type TZupdate.reg in the File name box.
1.5. In the Save as type box, click All Files, and then click Save.
2. Import this registry key on target machines by double clicking in the TZupdate.reg and clicking ‘Yes’ when prompted. All machines (clients and servers) must be updated with this registry information.
2.1. After importing the registry key, a new time zone named “(GMT+04:00) Port Louis” will be created.
The new time zone “(GMT+04:00) Port Louis” contains the DST dates for Mauritius.
2.2. Users located in Mauritius will need to change the time zone to the new “(GMT+04:00) Port Louis” time zone.
2.3. Note that on the new time zone, the option “Automatically adjust clock for daylight saving changes” is selected by default. Users should not uncheck this option.
3. In order to deploy these time zone changes in a corporate environment, you can use a startup script as described in the session “Deploy the registry file with the new DST information using Group Policy” below.
1. Click Start, click Run, type notepad, and then press ENTER.
2. Copy the following code, and then paste it into the Notepad document.
regedit /s \\contoso.com\NETLOGON\TZupdate.reg
Note: You must replace the \\contoso.com notation above with the actual DNS domain name for your Active Directory domain.
3. On the File menu, click Save As.
4. DST2008Update.cmd in the File name box.
5. In the Save as type box, click All Files, and then click Save.
6. Copy the following files to the Netlogon share folder of the domain controller that holds the PDC emulator role in the domain: - TZupdate.reg - DST2008Update.cmd
7. Wait until Active Directory replication occurs. Also, wait until the files and folders in the system volume (SYSVOL) shared folder replicate to domain controllers in the domain.
8. Click Start, click Run, type control admintools, and then click OK.
9. Double-click Active Directory Users and Computers.
10. Select an Organizational Unit (OU) which contains the computers that you want to apply this script to. In this example, we will use an OU that is named DST2008-W2K. This example also assumes that this OU contains computer accounts.
11. Right-click the DST2008-W2K OU and then click Properties.
12. Click the Group Policy tab, click New, type DST Registry Update, and then press ENTER.
13. Click Edit. The Group Policy Object Editor tool starts.
14. Expand Computer Configuration, expand Windows Settings, and then click Scripts (Startup/Shutdown).
15. Double-click Startup, and then click Add.
16. In the Script Name box, type the universal naming convention (UNC) path of the DST2008Update.cmd file that is located in the Netlogon share. For example, type \\contoso.com\NETLOGON\DST2008Update.cmd.
17. Click OK two times.
Note: Client computers that are within the DST2008-W2K organizational unit will run the startup script the next time the machine starts up. This will make the system to recognize the existence of the new “(GMT+04:00) Port Louis” time zone, however you still need to move to the new time zone that was just created. Please read the section ‘Changing the computer time zone via startup script’ for information on how to automatically change the time zone using a group policy.
2. Copy the following lines, and then paste it into the Notepad document.
ver |find /i "6.0">nul
IF %errorlevel% EQU 0 GOTO end
control.exe timedate.cpl,,/Z Mauritius Standard Time
4. Select a destination, and then type ChangeTZ.cmd in the File name box.
6. Copy the file to the Netlogon share folder of the domain controller that holds the PDC emulator role in the domain.
10. Select an OU that contains the computers that you want to apply this script to. In this example, we will use an OU that is named DST2008-W2K. This example also assumes that this OU contains all computer accounts.
11. Right-click the DST2008-W2K, and then click Properties.
12. Click the Group Policy tab, click New, type DST Time Zone Change, and then press ENTER.
16. In the Script Name box, type the universal naming convention (UNC) path of the ChangeTZ.cmd file that is located in the Netlogon share. For example, type \\contoso.com\NETLOGON\ChangeTZ.cmd.
a. You can import the registry key detailed above in any Windows Operating system language. However since it contains display information, the new time zone display names will be based on the “English US” language, as follows:
b. The information on “Deploying the registry file with the new DST information using Group Policy” session can be applied to all computers in the network.
c. The information on “Changing the computer time zone via startup script” should be applied only to computers located in Mauritius.
d. The instructions above can be applied on Windows 2000, Windows XP and Windows Server 2003 Operating systems, however after performing these instructions on a Windows 2003 operating system, the current time zone may not be automatically changed to the “(GMT+04:00) Port Louis” time zone. Users may need to change the time zone manually after importing the registry key via startup script on Windows 2003 machines.
e. The instructions above are not supported on Windows Vista or Windows Server 2008 operating systems.
Windows Mobile devices will show all items (messages and appointments) 1 hour off during the DST period (October 26, 2008 to March 29, 2009).
These devices require an update that is not available at this time. Information will be released as soon as it becomes available.
Three factors affect the scheduling of a meeting and appointment in Outlook:
Outlook time stamps the message request with the Greenwich Mean Time for the meeting. Outlook calculates Greenwich Mean Time by using the computer's clock time, plus or minus the local time zone adjustment, minus (depending upon the time of year) the daylight-saving time adjustment. If any of the three factors listed above are incorrect at the time the item is saved or if there is a modification afterwards (such as a DST change), the meeting time will be incorrect.
In the Mauritius scenario, after moving Windows clients and servers to the new time zone “(GMT+04:00) Port Louis”, Outlook calendars will display items 1 hour ahead their actual time during the DST period (October 26, 2008 to March 29, 2009).
In addition, because there was a time zone move, all appointments need to be updated to reflect the new time zone information. As such, "rebasing" of the items will be required to allow them to display the proper time and the proper time zone information. The Time Zone Data Update Tool for Microsoft Outlook can be used to update your calendar items to the new time zone “(GMT+04:00) Port Louis”.
What can I do to fix my appointments?
The Time Zone Data Update Tool for Outlook must be used with the /PHYSICALMOVE command-line parameter, which is not the default mode for the tool and, perhaps most importantly, not the mode in which the tool is launched automatically during setup.
Many of the special command-line options available for the Outlook tool are not supported when doing a time zone move. Most notably, /QUIET mode is not supported and the procedure needs manual intervention from the end-user.
The following describes the ideal set of steps to be followed by end-users performing a time zone move:
NOTE: As with standard time zone updates, the tool defaults to updating affected items on your Calendar and in your Reminders folder. If you would like to update additional items (e.g. items in additional Calendars or a PST), you can do so by clicking the ‘Custom…’ button and manually selecting the target folder.
The tool will inspect your mailbox and will report how many appointments will be moved:
If you click “Details” the appointment list will appear and you will be able to select all (default) or some of the appointments. In a normal situation you will move all the appointments to the new time zone. Click “OK” in the following dialog to proceed moving the appointments. A log file “Outlook Time Zone Update .log” will be generated in the %temp% directory.
What is the best time to update my calendar?
The best time to update your calendar items is as soon as you have changed your time zone settings in your operating system and before any new calendar item is created, accepted or sent.
Can I use the “Exchange Calendar Update Tool” to update (rebase) the appointments/meetings on the Exchange Server?
You cannot use “Exchange Calendar Update Tool” in the Mauritius scenario. The Exchange Calendar Update Tool is not designed to update appointments when there is a move from one time zone to another. The update has to be done on each client either manually or using the “Time Zone Data Update Tool for Microsoft Outlook”.
1. Do I have to update machines outside Mauritius?
It is recommended that you apply the registry updates to all machines, including computers and servers ones outside Mauritius particularly if you exchange Outlook Calendar items and other time dependent files that include references to local time in Mauritius. However, the time zone move should be performed only on machines located in Mauritius.
2. Should I manually adjust the machine’s clock on October 26, 2008?
You should not adjust the machine’s clock manually. This can cause adverse effects on your environment.
3. What calendar items will be updated using the Time Zone Update Calendar tool for MS Outlook?
Only appointments created using the original time zone “(GMT +04:00) Abu Dhabi, Muscat” which occur after the date/time the tool is executed.
5. Should I move to the time zone “(GMT +05:00) Ekaterinburg” on October 26, 2008 and move back to “(GMT+04:00) Abu Dhabi, Muscat’ after March 29, 2009?
This is a feasible workaround for home users; however it may not be the best option for corporations/enterprise customers as it can cause undesirable results on Outlook calendars.
One of the side effects from this workaround is related with appointments created in different time zones. For instance, appointments created before the change will be in “(GMT+04:00) Abu Dhabi, Muscat” and appointments created during the DST will be on “(GMT +05:00) Ekaterinburg”.
Another effect is that appointments created after March 29th 2009 during the DST time will be off by one hour when the user go back to “(GMT+04:00) Abu Dhabi, Muscat”.
If users move to the “(GMT+05:00) Ekaterinburg” timezone, they will have to run the Time Zone Data Update Tool for Microsoft Outlook in Physical Move mode. If then they move to the new “(GMT+04:00) Port Louis” time zone, they will have to run the Zone Data Update Tool for Microsoft Outlook in Physical Move mode again
There may be more side effects on this workaround; this option was not thoroughly tested.
We are considering options for how we will address the change in Mauritius in our December 2008 DST & Time Zone update.
We will issue more formal alerts on this news item this month as we have done for other countries that made late-breaking changes to the Microsoft DST & TZ Site, specifically on the DST Hot Topics and Latest News page. Note that other DST and time zone changes, the decision in Mauritius may impact customers doing business in and with the affected region.
As noted previously (and included on our Hot Topics site), Microsoft will continue to adhere to the published release cadence and issue the next update to DST rules and time zones in the December release. We will provide updates on the Microsoft DST & Time Zone site, issue appropriate alerts, and work with our subsidiaries to provide localized guidance based upon the work done we've done for other regions in the past (as we did for Argentina last year). We have started this effort to allow customers enough time and information to ensure that they make the appropriate plans for their organizations.