The standard dates for North American Daylight Saving Time (DST) change in March 2007. When the DST dates change, BlackBerry® devices will not update their clocks for the affected time zones if no patches for impacted BlackBerry software and third party software are applied. As a result, your BlackBerry device might not display correct time zone information for certain time periods during the year.
A website has been created that contains updated, clarified, and more detailed information around the upcoming United States and Canada Daylight Savings time change starting March 11th, 2007 and how RIM plans to address any necessary software changes or patches for various platforms. This new content replaces the previous Technical Advisories and Knowledge Base articles on the topic.
For more information: http://www.blackberry.com/select/dst2007/index.shtml
DST 2007 Patch download: http://www.blackberry.com/DST2007/patch/index2.shtml