I tried this out using Colins original hack and it comes up with a thread title that is one day off of the event. The "posted by" on the thread view is also blank. I ended up trying Kirby's code as well and the username shows up but the date is 1 day off as well.
Edit: After digging through the calendar.php file I assume this is because I am using a single all day event. If I do the ranged event it comes up correctly. I guess when it gets the single all day event it starts the previous day plus how ever many hours. Anyways anyone have an idea on a simple fix for it