Ever since the March 2009 DST the last weekend, outside appointments coming in from other time zones are off by 1 hour. For example, I am in Central Zone ... if someone from Eastern schedules an appointment for 2PM EST, it should post to my calendar as occurring 1PM CST. Instead, it still show up as 2PM CST. I have Exchange 2003 on a Windows 2003 Server and am using Outlook 2003 and 2007(problem happens on both versions). I believe I have all of the patches installed on both workstations and the server. Server is correctly set to Central and to adjust for DST and so are the workstations. The timezone in Outlook is also correct. All email shows up with the correct Time and Date stamp.
Read this post as well about what to do if just out look is affected I believe its called the TZmove.exe from microsoft to fix when outlook is off
https://www.experts-exchange.com/questions/22149674/DST-patch-for-Outlook-and-Exchange.html