Paraguay DST 2013 Fallback Update

Disclaimer:  The information in this document is written in response to an announcement by the government of Paraguay about changes in the daylight saving time for the year of 2013.

The steps provided in this bulletin were created to mitigate the impacts that the daylight saving time changes will cause for customers in Paraguay. 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 document might receive additional testing. 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.

Special notes: The official decree changing the DST dates in Paraguay is published by the government on the following site:

Paraguay DST 2013 Fallback

The government of Paraguay announced that for the 2013 DST period will be reduced. With this, DST will end on March 23rd, 2013 at 23:59:59. This means that clocks will backward 1 hour 3 weeks before the original date.

Since the new date published by the government is different from what was defined in the previous years, Windows-based computers will not correctly interpret the time that is related to the transition to daylight savings time.

In addition to Microsoft products, other software, OS releases and hardware (phones, routers, switches and managed devices) may require updates and/or changes.

Our teams at Microsoft have taken several steps to alert customers and partners about the changes in Paraguay.

Microsoft has released hotfix KB2829069 that covers all supported operating systems: Windows XP, Windows Server 2003, Windows Vista, Windows Server 2008, Windows 7, Windows Server 2008 R2, Windows 8 and Windows Server 2012.

For Enterprise customers that are using WSUS and SCCM, we encourage them to start using the Catalog option as it will help to deploy this hotfix on their systems. Catalog option can be used visiting link This option is only available for Windows 7, Windows Server 2008 R2, Windows 8 and Windows Server 2012.

Catalog option is not going to be available for this specific hotfix as we previously announced, we apologize for the inconvenience caused.

General recommendations

  • Install the hotfix KB2829069 as soon as it is available.
  • Please note that if you adjust the machine’s clock manually, you may have adverse effects on your environment. This procedure is not supported by Microsoft.
  • Contact Microsoft Support prior to any modification if you are unsure about the steps to follow in order to be prepared for the Daylight Saving Time change in Paraguay.

How to correct Outlook calendars

Customer needs to follow the steps described on KB931667 to update Outlook calendar. Also, you can refer to the following article “Daylight Saving Time Help and Support Center”.

Recommendations to minimize the impacts on Outlook/Exchange:

  • Simulate the changes on a lab environment, so you know what will happen and what to expect.
  • Work in conjunction with the operating system team to update the DST dates as soon as possible to minimize the chance of users creating new appointments during the delta period before the operating system DST dates get updated.
  • Before doing any change on the DST information, request the users to print their schedule so they have a reference to follow in order to manually update the appointments later if needed.
  • Take a full online backup of your Exchange Servers in case you decide to use the Exchange Calendar Update Tool.
  • For the meetings with multiple attendees only the meeting requestor should update the time and send the update to the others.
  • Include the time of the meeting in the e-mail request so that invitees can double check the correct meeting time (such as, "Project brainstorming - 11:00 A.M. Asuncion Time").
  • Exercise caution with the appointments and meetings in the extended DST period. When in doubt, verify the correct time with the organizer.


941018 How to address daylight saving time by using the Exchange Calendar Update Tool;EN-US;941018

934001 A troubleshooting guide to the Exchange Calendar Update Tool (Msextmz.exe);EN-US;934001

931667 How to address time zone changes by using the Time Zone Data Update Tool for Microsoft Office Outlook;EN-US;931667

943390 Some Outlook calendar items are rebased incorrectly when you use the Outlook Time Zone Data Update Tool to adjust for daylight saving time changes in certain time zones;EN-US;943390

Note: This is a "FAST PUBLISH" article created directly from within the Microsoft support organization. The information contained herein is provided as-is in response to emerging issues. As a result of the speed in making it available, the materials may include typographical errors and may be revised at any time without notice. See Terms of Use ( for other considerations.

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