We have reports (thanks, Jose!) that Venezuela will move to a newly created time zone, shifting by 30 minutes to -4:30h UTC on December 9th. For those of you keeping score, that’s at least the seventh change to the start date.

According to news reports on the official Venezuelan government news site, (see http://www.windowslivetranslator.com/BV.aspx?MKT=en-US&lp=es_en&a=http%3A%2F%2Fwww.abn.info.ve%2Fgo_news5.php%3Farticulo%3D111435%26lee%3D7 for an English translation) Venezuela will change to a new time zone on December 9th, subject to "constitutional reform." 

As previously noted, the updated Venezuelan time zone is included in the hotfix available via KB 938977 (see below).  We expect that customers should move their Windows clients to the new time zone after this new time zone goes into effect: at that time, clocks should be moved back 30 minutes, from UTC -4:00 to UTC -4:30. We expect that this change will begin at 11:59:59 PM local time on the start date, when non-system clocks should be moved back to 11:30:00 PM rather than advancing to 12:00:00 AM (midnight).  

[Correction (112907): the change will occur at 3:00AM on Dec 9th. More info coming soon on the DST & TZ hottopics page at http://support.microsoft.com/gp/dst_hottopics.]

Further, we expect that December 9 will be the official change date for the time zone and will follow up with more detailed information as it is available, around Dec 2.

What to do now: 

KB Article 938977 provides more information on how customers may request the hotfix update for the Windows operating system (available now) to allow customers and partners to test and implement the new time zone for Caracas, Venezuela, prior to an official move to the new time zone.

Updating Calendar items following the change with the Outlook TZ-DUT:  As previously noted, documentation is available around how to remediate regions such Venezuela using the Outlook Time Zone Data Update Tool (affectionately known as the "TZ-DUT" or "Outlook Tool") for the upcoming change in the blog post on time zone moves at http://blogs.technet.com/dst2007/archive/2007/10/04/time-zone-move-and-the-outlook-time-zone-data-update-tool.aspx.  

In Venezuela, after moving a Windows client to the new time zone, Outlook calendars will display items in the "wrong" place after the time zone move.  As such, "rebasing" of the items will be required to allow them to display at the proper time.  Here are detailed instructions for using the Outlook TZ-DUT to move your calendar items to the new time zone.  These instructions will be included in a future knowledge base article (currently being written). 

Please see the top-level customer guidance/ information provided on the DST & TZ hottopics page at http://support.microsoft.com/gp/dst_hottopics on potential challenges customers may have during this change.  

News articles:  

http://www.el-nacional.com/www/site/detalle_noticia.php?q=nodo/3284 http://buscador.eluniversal.com/2007/11/23/ccs_art_estudian-cambiar-hus_609836.shtml http://www.minci.gov.ve/noticias_-_prensa/28/16725/venezuela_podria_tener.html http://www.mct.gob.ve/publico/noticias/det_noticias.php?co=1249 http://www.abn.info.ve/go_news5.php?articulo=111435&lee=7

Tags: Microsoft, Daylight Saving Time, Daylight Savings Time, DST. 4,020,000; 10,600,000; 649,000+