Available now: December 2014 cumulative time zone update for Windows operating systems

Is it December already? That means that holiday treat we know at the December cumulative time zone update for Windows operating systems is out, available as kb 3013410. As noted, this update replaces the previous August 2014 CU 2981580 and includes all the time zone and daylight saving time changes released as hotfixes since then, including the monumental changes we saw in Russia in October. (ICYMI, Se my post from September.)

The following changes were made since the previous Windows cumulative time zone update:

  • Russia time zones: Russia announced that it would change its existing time zones on October 26, 2014. This change included seven updated time zones, three new time zones, and two existing time zones that merged into one.       (     
  • Fiji Standard Time: Fiji announced that the country’s new daylight saving time (DST) schedule would start on November 2, 2014 and end on January 18, 2015. The previous DST start date in Windows for the Fiji time zone was October 26.(     
  • Cape Verde Standard Time: We have changed the name of the “Cape Verde Standard Time” time zone to “Cabo Verde Standard Time.” The display name for this time zone is now “(GMT-01:00) Cabo Verde Islands.”

So what should you do to make sure that your computers are ready for the change?

Most applications and services reference the underlying Windows operating system for their date and time related rules, with some exceptions. We outline the various software updates to select Microsoft products (including various releases of the Microsoft Windows operating systems, Microsoft Office and other applications) on the Microsoft Daylight Saving Time Help and Support Center. There, we have information and links to updates for various products in mainstream and extended support affected by this change, as well as other various changes to DST offsets and time zones around the world.

If you use Microsoft Update on your PC at home, chances are you’re already covered. The latest update from October may already be installed on your PC if you have turned on Automatic Update in Windows. This ensures you’ll get the latest security and other important updates from Microsoft automatically. If you’re not sure if the update has been applied, visit the Microsoft Update site for more information.

If someone manages your network at work, it’s likely the needed updates are schedule to be deployed to your computers and devices, if they haven’t been installed already.

For IT professionals managing PCs, servers and Microsoft software installations, please visit for more details. Also, visit the support websites of any other software companies to see if you need to apply any updates. It’s not just Microsoft software that may require updates. Additionally, for the latest change in Russia, we provided specific details and guidance at

While Microsoft’s Services infrastructure will be updated to reflect DST changes, it’s important that your computers — both clients and servers that interact with these services — also have the latest Windows cumulative updates for DST and time zone changes applied in order to ensure data integrity.

As always, thanks to the good folks in Windows and those across the company working to help manage time… particularly the number of daylight saving time and time zone changes that come in from various corners of the world. You can find this and much more documented over at and over on the Windows blog at