http://blogs.technet.com/hied_west_blog/archive/2007/02/23/dst-update-exchange-calendar-update-tool-revised-february-22-2007.aspxThe DST 2007 and Exchange product group have released an updated version of the Exchange Calendar Update Tool: http://support.microsoft.com/?kbid=930879 . Download Center: http://www.microsoft.com/downloads/details.aspx?FamilyId=A9336886-4B28-4010-9416-36D38429438D&displaylang=enenCommunityServer 2.1 SP1 (Build: 61025.2)