I noticed (after missing an appointment) that my calendar entries were appearing in my calendar on the wrong days. Took me a while to work out what was going on - but here it is. If anyone knows a fix, or has experienced the same thing, I'm interested to know. Maybe I just have a dud Ipad. Assume you have an all day entry in your calendar - let's say starting from the 9th of the month and ending on the 15th of the month. You want to enter a new event on the 14th. You open up the calendar, then open up the month view, then double click on the 14th. You then enter your event and click add. It goes into your calendar on the 9th - ie the first day of the current all day event - not the 14th. This seems to work in all cases except where the start of the all day event is on or before the current day. I've just upgraded my Ipad to an IPad Air. Frustrating to find something basic like the calendar cannot be trusted.