I just notice all iCal data prior to August 2010 is erased from my iCal. I have a backup of the data, but don't know 1) where to locate the file and 2) how do I restore it without losing the appointments SINCE that backup? Also, I have no idea why this happened. Obviously I didn't erase it all... Any help? UPDATE: So I restored via time machine my previous calendars. However, now the problem is my iCal shows one set of calendars as "on my mac" and then another set "my mobileme account." I can't just delete one of them because some appointments are on one and not the other. I also now have duplicates of my appointments after the date of the file from which I restored. Ug.