For many users, this is not likely to be greeted as welcome news. Rightly or wrongly, there is a widespread belief that the new service is more trouble-prone than the old one and that the best way to avoid the trouble is to avoid the upgrade. I covered some of these concerns in a . Unfortunately, this avoidance strategy will no longer work as of May 5.
My best advice at this point is to upgrade as soon as possible. Don't wait until the last minute. Here are a few personal tips to assist in your transition:
1. According to Apple, you should be running at least Mac OS X 10.6.4 and iOS 4.2, on your Mac and iOS devices respectively, to be compatible with the new Calendar service. If you haven't already upgraded, do so. If your hardware is not compatible with these software versions, it's time either to consider a hardware upgrade or look for a third-party calendar alternative.
2. Make sure that your Calendar data is backed up. If you don't perform a regular automatic backup of your drive's contents, archive your iCal data (via the Export command in iCal's File menu). That way, if anything goes dreadfully wrong with the MobileMe transition, you should be able to recover.
3. Begin your upgrade process at the . Just click the "Upgrade now" item on the Calendar page. If you don't see this option, you're already using the new Calendar. After a bit of a wait, the new Calendar should appear. You're done!
The one glitch I have had here is that the upgrade process may take an unusually long time, with the spinning wheel seeming as if it will never stop. Be patient. However, if you eventually believe something has gone wrong, you can log out of MobileMe and log back in. When I did this, I found that the upgrade had successfully completed; the new Calendar happily appeared. Otherwise, you can select to upgrade again.
4. Assuming you've already been syncing your calendars via MobileMe, when you next launch iCal on your Mac, iCal should automatically update your calendars to reflect the change. In particular, your calendars will now be listed under a "yourname@me.com" heading. If not, check out this or this for advice.
5. Go to System Preferences and open the MobileMe pane. From the Sync tab, uncheck the Calendar option. As you are no longer syncing calendars via Sync Services on the Mac, this option is no longer needed.
6. If you also sync your calendars to iOS devices, go to the Calendar app on each device. If all has gone well, the app should automatically reflect the new calendar service. If you see the same calendar(s) listed more than once, or otherwise have problems, check out the same two Apple articles cited above. For me, the key remedy has been to go to the MobileMe account settings in Settings -> Mail, Contacts, Calendars; tap the Calendar slider off; and choose to delete data when asked (this assumes your data remain at me.com). When you turn the slider back on, calendars should now display correctly.
7. Finally, if you use BusyCal, you'll have some additional work to do. In fact, don't even begin the transition until your read this .