August 2011 cumulative time zone update for Windows operating systems

The update that this article describes changes the time zone data to accommodate daylight saving time (DST) changes in several countries. This update also includes other DST-related changes, time zone-related changes, and settings-related changes. Some of these changes have occurred since the products that are listed in the "Applies to" section were originally released.

from Microsoft Support - Windows XP https://ift.tt/3ec9iV5