I have read through many of these posts on daylight savings time and Outlook.
We have the same problem. Users entered appointments without daylight savings checked. Now we need it checked off and all appointments that were set to "all day" now span two days.

I called support and described the problem 10 times. The rep just kept telling me to turn off dayligfht savings and deal with the clock being off. How ridiculas. She would put me on hold for 15 minutes and then come back to tell me this issue was done by design and there isn't any problem. KB artical 197718 states that this is a known problem. I finally hung up after two hours of being told to live with the problem. Now I found another article descibing how to export and import into the new time without affecting appointments. I tried exporting to a PST and re-importing and had the same problem. Artical 197480 describes the exact process but instead using a CSV file for the export. I am trying this now.

What is Microsoft's position on this? Just another bug they can't fix?