I updated my MacBook yesterday, OS X 10.9.1 some of my calendars are now not syncing with my ical on my iPhone 4s. I have tried everything in the troubleshooting. Any ideas?

Hey there Clare,

It sounds lik eyou are using iCloud to sync calendar events to your iPhone from your computer but after a recent OS update, the syncing has not worked correctly. I would start by using the troubleshooting for iCloud calendars with the following article:

iCloud: Troubleshooting iCloud Calendar

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

Troubleshooting on OS X

Confirm that you've turned on iCloud Calendar:

1. Choose System Preferences from the Apple menu (), then click iCloud.
2. If you're using OS X Mavericks v10.9 or later, make sure that the Calendars checkbox is selected.
3. If you're using OS X Mountain Lion or Lion, make sure that the Calendars & Reminders checkbox is selected.

Try each of these steps, testing after each to see if the issue is resolved:

• Make sure that you are using OS X Lion v10.7.5 or later. Learn how to verify the version of OS X you are using.
• Make sure your computer is online. Attempt to view www.apple.com. If you can't connect to the Internet, your iCloud calendars and events will not update in Calendar or iCal. Learn how to troubleshoot your Internet connection.
• Open a secure website to test if ports 80 and 443 are accessible. Calendar requires port 443 access to iCloud in order to push and fetch updates to and from the iCloud Calendar servers.
• Choose Apple () menu > System Preferences, then click the icon for iCloud. Make sure that you're signed in to the same iCloud account that you're using on your other supported devices.
• Make sure that you enter and update calendar information in the iCloud section of Calendar or iCal. Only calendars and events in the iCloud section of the Calendar or iCal Calendar list are updated in iCloud. Both Calendar and iCal for Mac support the display of and interaction with multiple accounts and datastores, such as iCloud, On My Mac, Exchange, and Google. This makes it easy to create or modify events or calendars in a section of Calendar or iCal that may not be updating iCloud. Learn more about moving local calendars to iCloud.
  • In some cases, you may find that you have data duplicated in both the local On My Mac and the iCloud sections of Calendar or iCal. Learn more about resolving this issue.
  • You can make the iCloud calendar your default calendar for all new events. In Calendar, choose Calendar > Preferences, then click General. In iCal, choose iCal > Preferences, then click General. Locate the Default Calendar setting and choose one of the Calendars under the iCloud heading. Close the Preferences window to save the change.
• If recent changes don't appear, try forcing Calendar to refresh by selecting Refresh Calendars from the View menu. In iCal, select Refresh or Refresh All from the Calendar menu.
• 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. ChooseApple () 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.

Cheers,

Sterling