How to configure daylight saving time for Microsoft Windows operating systems

Applies to: Windows Server 2012 R2 FoundationWindows 8.1 EnterpriseWindows 8.1 Pro


Daylight saving time implementation varies from country to country. Some countries may not observe daylight saving time (DST), whereas other countries may change the start dates and end dates for daylight saving time every year. This article describes how to update Windows to use the latest DST and global time zone rules.

These updates apply to the following operating systems:

  • Windows Server 2012 R2
  • Windows 8.1
  • Windows RT 8.1
  • Windows Server 2012
  • Windows Server 2008 R2 Service Pack 1 (SP1)
  • Windows 7 SP1
  • Windows Server 2008 Service Pack 2 (SP2)

Updates that have been issued

The following daylight saving time updates have been issued for Windows since 2010.

Note The cumulative updates are rollups of all previous changes. The latest cumulative update is the only one that is required. The old updates do not have to be explicitly installed.


In many countries, the start dates and end dates for daylight saving time (DST) change from year to year. Additionally, countries may change their policy of how they recognize daylight saving time, or they may change the local time offset from Coordinated Universal Time (UTC).

This article contains information about how to update the registry in Microsoft Windows to accommodate these kinds of ongoing changes. All computers should be updated to include these time zone updates regardless of whether they are located in a changing time zone. This is because some applications may use the local time zone database to perform date and time calculations for events that occur elsewhere in the world.

Please install the time zone updates as soon as possible. This minimizes the number of delays that will be experienced by Outlook and Exchange meetings or calendar events that are scheduled during that period.

Latest DST update

For the latest daylight saving time update for Windows, see the following Microsoft Knowledge Base article:

4578623 DST correction in Windows for the Fiji Islands: October 13, 2020

DST help and support

The samples in this article update the global time zone rules that are used in Windows as of December 2011. For more information about how daylight saving time changes may affect other Microsoft products, go to the following Microsoft website:


For more information, see the following articles in the Microsoft Knowledge Base:
256986 Windows registry information for advanced users
310516 How to add, modify, or delete registry subkeys and values by using a registration entries (.reg) file
100010 What are Control Sets? What is CurrentControlSet?
322756 How to back up and restore the registry in Windows
310516 How to obtain Microsoft support files from online services

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