Q: How can I restore deleted items to my iMac which are still in the calendar in my iCloud?

Hello there,

It sounds like you have verified that your canlendar data is stored in http://www.icloud.com and would like to get that info back into your calendar application on your computer. I would start by using the troubleshooting in the following article named:

iCloud: Troubleshooting iCloud Calendar

http://support.apple.com/kb/ts3999

• Make sure that your account was successfully created in Calendar (or iCal) on your Mac. After upgrading to iCloud Calendar, you may need to quit and reopen Calendar (or iCal). To confirm that your account is configured correctly in Calendar (or iCal):
  1. Open Calendar (or iCal).
  2. Open Calendar (or iCal) Preferences.
  3. Click Accounts. You should see an account with your iCloud member name in the Apple ID field.
• Turn iCloud Calendars off and back on:
  1. Quit Calendar (or iCal).
  2. Choose Apple () menu > System Preferences, then select iCloud.
  3. Deselect the checkbox next to Calendars (or Calendars & Reminders in Mountain Lion and Lion).
  4. Close System Preferences and wait about a minute.
  5. Open System Preferences and select iCloud.
  6. Replace the checkmark next to Calendars (or Calendars & Reminders in Mountain Lion and Lion).
  7. Close System Preferences.
  8. Open Calendar (or iCal) and test to see if the issue is resolved.
• Restart your computer. This may sound simple, but it reinitializes your network and application settings and can frequently resolve issues.

Thank you for using Apple Support Communities.

Take care,

Sterling