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Daylight Saving Time Help and Support Center
Help and support on how to update your Windows computer for Daylight Savings Time (DST).
What is Daylight Savings Time (DST)?
Daylight saving time (DST), and "Summer Time" in much of Europe, is the practice of moving local time forward one hour in the spring and backwards in the autumn. These spring and autumnal shifts to DST are different between northern and southern hemispheres. The start of DST in the northern hemisphere is usually in March or April (depending on the country/continent), and ending in October or November. In the southern hemisphere, the changes are the opposite, with DST beginning in October and ending in March or April.
What does this mean for me?
It is important that the time zone settings for your computer's system clock and your calendar programs are updated. For your home PCs the most important action you can take is to ensure you are using Windows Update. Choosing to automatically update your operating system via Windows Update will give you a seamless transition to the new Daylight Savings Time and Time Zone settings. Guidance on how to update computers and installed Microsoft products is available here.
DST Hot Topics & Latest News
Notice: 2012 DST Changes for Morocco
Notice: Armenia Cancels DST
How do I update my computer?
Small or Medium Business
If you are a Partner updating your own systems or assisting customers to update their systems partners should refer to the IT Professional guidance. Further support for Microsoft Partners is available through the following:
To update your code for Daylight Saving Time, visit MSDN: Visual Studio and Daylight Saving Time Change to find the correct information.
Updating Exchange and Outlook Calendars
Recommended sequence of DST update actions for Windows, Exchange and Outlook
Calendar environments have an interconnected system of applications, and each environment must be adjusted to accommodate the new DST rules. Please note that KB articles may be superseded. Please review the documentation carefully before you apply any updates.
There are many supported combinations of Exchange Servers and Outlook Clients. The approach that customers should take to update their calendaring environments is dependent on these combinations. The following table shows the high level requirements for rebasing Exchange/Outlook calendars for each of these combinations.
All the guidance on this page should be reviewed in order to understand the appropriate sequence of actions customers should take, including the updates that should be applied prior to rebasing calendars.
The following items should be noted to help ensure maximum accuracy of calendar updates:
The IT administrator has one of four alternatives (pros and cons of each alternative are described later in this article):
Available DST and TZ Updates for Microsoft Products
List of products and services affected by daylight saving time
Detailed update information and downloads
Windows Server and Client
Windows SharePoint Services
SQL Server Notification Services
Important information for users who have Groove workspaces: After this change, users should communicate to verify and adjust start times and end times of Groove Meetings tool meetings and Groove Calendar tool appointments. Also, users should be aware that time stamps may appear incorrectly in other Groove tools such as Discussion, Forms, Chat, and messaging. For more guidance on resolving or working around these problems, refer to the DST KB articles listed below for your specific version of Groove.
Microsoft Dynamics CRM
Windows Mobile and Windows Phone
All updates for Windows CE are available from the Windows Embedded Download Site
Entourage and Outlook for Mac
To ensure you have the latest updates for Daylight Savings Time and Time Zone changes you can do one of the following:
Windows Services For Unix (SFU) and Subsystem for UNIX-based Applications (SUA)
Microsoft Policy in Response to DST/TZ Requests
Microsoft Windows has established an annual update schedule for daylight saving time (DST) and time zone (TZ) releases. Most Windows-based applications (and some services) reference the underlying operating system for DST/TZ information, but some applications and services do not. Hence many of our product teams also follow an annual product update cadence such a Windows, with provisions for semi-annual cumulative updates as needed. For each update release, Microsoft accepts change requests up to a few months (generally four to six) prior to the release date. The Windows Release schedule provides a regular cadence for other product groups to follow.
Following the Windows regular cadence for publishing newly legislated DST rules and TZ updates, cumulative DST and Time Zone updates are scheduled for release each December (to the Microsoft Download Center and to Windows Update) for the coming calendar year as long as there are time zones affected. When needed, Microsoft product groups may also provide a semi-annual update in the August/September timeframe. The product group will also publish the new or modified TimeZoneInformation (TZI) keys in an update to Microsoft KB article 914387 for IT professionals and systems administrators who may need that information. Microsoft hopes that this will provide a more predictable way for customers to anticipate and plan for our scheduled product updates as they are published.Recommendations
In order to achieve more seamless transitions to new DST and time zone policies, Microsoft requests that governments provide the following:
Customer requests and the Microsoft DST/TZ Support Policy
On occasion, when there are extreme circumstances that require a change to a time zone, Microsoft may make an effort to provide a solution to the customers in the impacted regions through an Out-of-Band (OOB) Release. Any such package may include a Windows hot fix and a documented Outlook solution through the TZMOVE tool. Where a temporary workaround for customers exists Microsoft may recommend using the workaround until the Cadence Release is made available.
When DST and Timezone changes occur Microsoft often produces webcasts to support customers. These webcasts include the guidance provided on this site and the Q&A sessions with customers. The DST Webcasts page will continue to be updated as new webcasts are available.
Microsoft IT deployment guidance
The following guidance documents from the Microsoft IT Department cover a wide range of enterprise scenarios for DST change management. Guidance from both 2011 and 2007 is available all of which remains highly relevant to the broad range of customers and partners using different versions of Microsoft Products in their environments.
MSIT 2011 Guidance
MSIT Enterprise Response Plan
MSIT Russia DST Awareness Communication
MSIT 2007 Guidance
MSIT DST Assessment Checklist
MSIT DST Assessment Checklist
There are a number of useful blogs to keep customers up to date on DST\TZ changes in their region.
3rd Party Product updates