Just sent this to my customers, sorry you Mac guys are on your own 
To Fix your Server (Run from server, choose IT Professional) : Daylight Saving Time Help and Support Center
Beginning in 2007, daylight saving time (DST) will be extended in the United States. DST will start on March 11, 2007, which is three weeks earlier than usual, and it will end on November 4, 2007, which is one week later than usual. This results in a new DST period that is four weeks longer than in previous years. Unless certain updates are applied to your computer, the time zone settings for your computer's system clock may be incorrect during this four-week period. In particular, you must make sure that both your Windows operating system and your calendar programs are updated.
I recommend you run the following on all your machines, including your server.
All your workstations should be very easy to update, some of you that have a server may want to contact be on this.
To fix each workstation (Run this on each whether or not you use Outlook): http://office.microsoft.com/assista...d=XT102171261033&vwidth=600&vheight=450&type=flash&CTT=11&Origin=HA102086071033
To Fix your Server (Run from server, choose IT Professional) : Daylight Saving Time Help and Support Center
If you need my help, please respond ASAP, as the 11th is coming up very soon.
Of course, as I am no part of Microsoft, I cannot warranty nor guarantee this Fix. This email is for informational purposes only,and there is no support expressed or implied.