There have been a few times over the last few weeks that I've looked at an entry in the calendar on my iPhone and something hasn't looked quite right. It wasn't until today that I actually realized the problem, and it looks to me to be a bug in iOS 4: certain events in my calendar were supposed to show up on one day but instead showed up the day before in the List View.
For example, I had an "all day" entry on my calendar for today telling me that it was a friend's birthday and I had an 8am entry in my calendar for a meeting tomorrow morning. However, when using the List view in the Calendar app, the birthday was showing up on Monday August 2, not Tuesday August 3, and the 8am August 3 entry was showing up at the bottom of the list for entries for August 2. In the "Day" and "Month" views the entries showed up correctly, and if I tapped on a particular items all of the information was correct. It was just in the List view that things were askew.
A quick Google search pointed me to this page on Apple's website in the Support Discussions section. Apparently, I wasn't alone. Other people who synced their calendar either with Microsoft Exchange (which I do), with Google Calendar or with MobileMe were reporting the same problem. The recommended solution posted by several people was to go to Settings --> Mail, Contacts, Calendars --> [the name of my Exchange account] and then, on this screen, turn Calenders to OFF:
The iPhone warns you that this will delete all Calendar data from the iPhone, which is fine because all of my data was on my corporate Exchange server. I then turned the Calendars ON again, and my calendar entries started to download again from my server. It took a few minutes for all of the entries to be restored, but now all is well and birthdays and meetings and other events are showing up in the right place in my List view.
My hope is that this is the end of the problem for me, but I've seen others post that this is just a temporary solution and that the problem can return. The very last post on that thread, from "b-gee" on August 1, says: "Apple has responded to my bug report at bugreport.apple.com, saying that this is a known issue." Hopefully this is true and Apple is working on a fix right now.
For the time being, though, if you are looking at Calendar entries using the List view and something doesn't seem quite right, switch to the Day or Month view to see if entries are showing up different in those views. And if that is your problem, consider doing what I did and flush your Calendar data and then download it again it from your server.
