All of my all-day events are a day "early" on my iPad. This applies to all-day events I have entered manually, birthdays (which I can edit indirectly through the Address Book), and synchronized calendars from Apple (e.g., US Holidays). For events that I can edit, doing so corrects the problem (though even that would require hundreds of edits to individual events), but I can do nothing about synchronized calendars. Events in Lion Calendar, iCloud, and my iPhone calendar are on the correct dates.
Has anyone else experienced this issue or found a way to correct it?