Information on Daylight Saving Time, Time Zone and related DST changes for Microsoft Windows and other products in 2009

An update on some of the recent daylight saving time changes around the world coming this year to Morocco, Pakistan, Syria and Tunisia in 2009…

image It’s been a busy time, reflected in fewer than normal postings on this blog, but happily it’s due in part (when it comes to time) that there has been little to report in the area of changes to DST and times zones.

In past years, the move from Winter to Spring in the Northern Hemisphere would signal a change to clocks in much of Canada and the States. But as you may know (unless you’re an hour late to all your meetings) that the US and Canada "Sprang Forward" a few weeks ago:  March 8 marked the arrival of Daylight Saving Time.

So here’s a look at some of the changes we’re evaluating and how they would be included in future updates in various DST & time zone product updates (with provisions for semi-annual as needed as outlined here).

Morocco: As noted last year, once again the kingdom of Morocco plans to observe daylight saving time in the country, beginning on Sunday, May 31 at midnight, and ending on Thursday, August 20 at midnight. Not surprisingly, this coincides with the start of Ramadan. (I believe that Egypt will likely make similar changes, but we have no confirmed change in that country.) You can find more information on these changes on and this post on

Pakistan: Last May (2008), we learned of a change to the observance of Daylight Saving Time in Pakistan that could impact customers using local time zones, including entities engaged in business in or with the region.  Unfortunately, due to the short notice at which the change had been announced, Microsoft was unable to provide updates (hot-fixes) to support the implementation of DST and referred people to this post on the changes for more details.

For this year – unfortunately once again we don’t have any clear communication on changes in 2009. Through news reports, we estimate that we will learn more at the beginning of April. Once we receive an official notification, we will look at how to bet address the changes.

Syria: We have reports that daylight saving time will begin in Syria on March 27, 2009 at 00:00:00 this year according to many sources, this article in the Syrian Arab News Agency (English), and this article from, the government site. Guidance will be posted shortly on mitigating the changes in the country.

Tunisia discontinues DST in 2009: Recently we learned that Tunisia will no longer observe daylight saving time beginning in 2009, as noted by the Tunisian press agency here. Daylight saving time had been observed since 2006, beginning on the last Sunday of March, and ending on the last Sunday of October.

As noted in a prior post, our product teams are moving to a regular rhythm to update their products and services to reflect these time changes. (For each update release, Microsoft accepts change requests up to a few months prior to the release date.)

We’ve also updated our page on Microsoft’s Policy in Response to DST/TZ Requests, providing recommendations in order to achieve more seamless transitions to new DST and time zones policies. We suggest that governments should provide the following when considering changing DST or making adjustments to time zones:

  1. Ample advance notice (1 year or more) of the planned change.
  2. Official published confirmation of planned changes to DST or time zones.
  3. Concentrated efforts on promoting the change to the affected citizens.

Important note for governments: Let me note that in support of these types of changes, we provide guidance and Microsoft’s Policy in Response to DST/TZ Requests. It’s important for countries and territories to work towards seamless transitions to new DST and time zones policies, providing ample advance notice (of a year or more) with published confirmation of planned changes. In addition, we suggest that entities considering the changes consider implementing changes at the next clock tick after 01:59:59 rather than at 00:00:00. Making the change at midnight can impact daily systems, such as back ups, data pulls or other automated tasks.


Tags: Microsoft, Daylight Saving Time, Daylight Savings Time, DST, Morocco

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