The August 2013 DST Cumulative Update for Windows Operating Systems has been published on Microsoft Download Center. It contains the following changes:
New DST starts on the last Friday of March at 2:00 A.M., and ends on the last Friday of October at 2:00 A.M. This new DST rule is introduced in 2013 and the new dedicated time zone is also added (UTC+1 Tripoli).
New DST starts on the Friday before the last Sunday of March, and ends on the last Sunday of October at 2:00 A.M. This new DST rule is applicable from 2013 to 2023.
New DST ends on April 27, 2013, and starts on September 7, 2013. This new DST rule is applicable to 2013 only.
New DST ends on March 23, 2013. This change incorporates the shortened DST rules for Paraguay in 2013.
This change adds Ashgabat to the display name of the “West Asian Standard Time” time zone.
The change in the August DST Cumulative Update accounts only for History Correction after the DST 2013 Ramadan fix-it solution that was shipped in June 2013 (KB 2860495).
For more information on these adjustments, refer to this Microsoft Knowledge Base article: http://support.microsoft.com/kb/2863058.