2007 time zone update for SQL Server 2005 Notification Services and for SQL Server 2000 Notification Services
Starting in the spring of 2007, daylight saving time (DST) start dates and end dates for the United States will change to comply with the Energy Policy Act of 2005. DST dates in the United States will start three weeks earlier (2:00 A.M. on the second Sunday in March) and will end one week later (2:00 A.M. on the first Sunday in November).
The below Microsoft Technet article describes how to modify the time zone data for SQL Server Notification Services to account for the United States DST change.
http://support.microsoft.com/?kbid=931815&SD=tech