Announcement: Microsoft Windows December 2010 Updates to Daylight Saving Time and Time Zones

Check out Microsoft Knowledge Base Article 2443685, “December 2010 cumulative time zone update for Windows operating systems”, which the Windows team just posted.  This is the December Daylight Saving Time and Time Zone (DST & TZ) Cumulative Update (CU), and the current KB/blog text focuses on the less common changes, such as adding the timezone for Magadan. 
The good folks in Windows (thanks, KC) provided some additional commentary and clarifications to the posts…

  1. Explaining that the Namibia DST support changes begin in 2011
  2. Listing other regions with dynamic support which get routine annual updates

The December 2010 DST Cumulative Update for Windows operating systems focuses on the following changes:


  • A new timezone has been created for Magadan. The Magadan timezone has support for Daylight Saving Time, with 2011 DST running from March to October.
  • The existing timezone “(UTC +11:00) Magadan, Solomon Islands, New Caldonia” has been renamed “(UTC +11:00) Solomon Islands, New Caledonia”.   This is only a  displayname update – the rules for this timezone have not changed. As before, this timezone does not have DST support.
Namibia: The offset has been changed from UTC +2:00 to UTC +1:00. In addition, for 2011 and forward, the DST start date will occur in September, and the DST end date will occur in April.
Egypt :  the 2011 DST start date is set to occur in April and the DST end-date is set to occur in September. This is provided to address cases in which 2010 Fix-its for temporary DST changes were only partially applied.
In addition to these changes, the December DST CU contains 2011 adjusted DST start and end-dates for the following timezones:
·    Israel Standard Time
·    Morocco Standard Time
·    Pacific SA Standard Time
·    Samoa Standard Time
·    Syria Standard Time
For more information on these adjustments, refer to this Microsoft KnowledgeBase article: 
The following blogs have been updated  – the KB updates are coming :

For more information about how daylight saving time changes may affect other Microsoft products, click the following article number to view the article in the Microsoft Knowledge Base: 914387  ( ) How to configure daylight saving time for Microsoft Windows operating systems.

A holiday nod of thanks to the good folks across our company working on our effort to help manage time (particularly in daylight saving time and time zone changes) — documented and followed at and over at the blog at — and to the folks coordinating the efforts on our daylight saving time and time zone updates and releases for current products across the various product groups at Microsoft.  As noted, this is a tough job, to say the least.

Tags: Windows, Microsoft, Daylight Saving Time, Daylight Savings Time, RSS, DST; 18,600,000 (up a bunch from just six months ago); 18,800,000 (down ~2M)

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