How to restore ical with time machine

First, backup your other calendars in iCal by exporting them. These files will be your safety net in case something goes wrong.

Then quit iCal. In the Finder, go to (user)/Library/Calendars. You will see a folder for each of your calendars: you need to identify which one is your Work calendar (they have code names) - open each folder then the Events folder within:the one with only one item will be your work calendar (you can drag the .ics file to TextEdit to check what it is).

Go back to the Calendar folder. Enter Time Machine; go back to the time when the folder for your calendar was intact and restore.

Delete the Calendar Cache file in the Calendars folder.

Now you can start iCal.

I'm assuming you don't have a MobileMe account syncing with iCal. If you do, things get a lot more complicated and you need to read this page carefully first:

http://www.wilmut.webspace.virginmedia.com/notes/timemachine.html

As you're syncing with MobileMe, if you restore the calendar MobileMe will promptly wipe it again: so you will indeed need need to follow the procedure outlined in my page, turning off your internet connection before carrying out the TM restore.

I was able to follow all of this successfully under Lion and MobileMe. The restore works as expected as long as I have my ethernet connection deactivated. However, MobileMe zaps evertything as soon as I reactivate the network link. I have talen iCall "offline" and de-selected "Calendars" and "Synchronize with MobileMe" in MobileMe Preferences. I even removed the computer from the list of machines being synched. None of this works!

The evil demon that is MobileMe blasts almost all of my calendar data as soon as it can. Obviously, I can't stay disconnected from the internet to address this issue.

Please try this procedure which should put a stop to that problem:

http://www.wilmut.webspace.virginmedia.com/notes/timemachine.html

Making changes in System Preferences>MobileMe>Sync will have no effect whatever - this method hasn't been in use since May.

Thanks Roger but that didn't work for me. I followed this recipe with great care and even did it twice just to make sure. Perhaps the fact that I'm doing this under 10.7.1 has some bearing on the matter. At first, it appeared to be working but after a short wait, all of my newly constituted MobileMe catalogs except one (first on named Home) were empties and renamked "Untitled" and Untitled 1."

Another factor that may be relevant is that I seen iCal appear and disappear from the MobileMe list of things to synch. It's out of view 99% of the time. I'm suspecting that this might be connected with iCloud. I did briefly look at iCloud under 10.7.2 at work. I may have inadvertently set a trap for myself there.

Frank Lowney1 wrote:

Another factor that may be relevant is that I seen iCal appear and disappear from the MobileMe list of things to synch. It's out of view 99% of the time.

If you are talking about something you see in System Preferences>MobileMe then it's not relevant - iCal does not in fact sync, it reads the calendars directly from the server (though there is by default a cached local copy) and as I said the settings in that prefs pane are nothing to do with iCal any more.

iCal is controlled in System Preferences>Mail, Contacts& Calendars and you should check that your MobileMe login details are correctly entered there - please see http://support.apple.com/kb/HT4758

As to the process I detailed, in the first set of numbered instructions, please make sure that when you have exported your MobileMe calendars you import them back into a calendar listed under 'On My Mac' - these cannot be deleted by MobileMe and from your description it sounds as if you may not have done this. Given your problems, I would suggest choosing new name sfor the calendars, at least temporarily.

Then when you reconnect to the internet it should not be possible for MobileMe to delete the calendars and you can proceed with the next steps.

I mentioned that peek-a-boo iCal icon in MobileMe prefs as a possible indicator of vestigual code at work. In any event, I have confirmed that all data in System Preferences > Mail, Contacts and Calendars is correct.

After 2 of the 3 new MobileMe calendars were renamed to Untitled and Untitled1 by iCal, I renamed them back and that seems to have stuck. The one that was not changed, the default calendar, contains the imported (from On My Mac) but the other two are bereft of data.

When I try to import data into "Home", I get a 403 as follows:

Which isn't a big deal since the data was successfully imported in the first pass. The other two eventually accepted the import of data that had been exported from the "On My Mac" calendars gotten from TimeMachine.

So at last at at least things are back where they were last Sunday and I can get along from here. Thanks for the help.

This saved my life (not literally lol).

Thanks a million for your post!