How To Reset Calendar, iTunes USB Sync

Once, every so often (for no apparent reason) iCal or “Calendar” as its now known goes through a phase where it refuses to sync with your iOS device via USB. Point to note – this article is about local USB syncing.

Not iCloud.

That’s an entirely separate can of worms.

Firstly, we would like to point out that the majority of good samaritans out there seeking to help others suffering this inconvenience more often than not suggest turning iCloud Calendar syncing off and on again within your OS X’s System Preferences to resolve this.

That might work for iCloud syncing issues but since this is a USB sync issue – it doesn’t.

Added to that every time you attempt to turn off iCloud syncing you must delete all your existing Calendars on your Mac.

We recommend that the following be attempted in descending sequence because Calendar sync issues are so varied and random any one or a combination of the suggested solutions below might be the cure.

If one solution solves your issue, then stop and don’t attempt the next one.

#1. Clear Calendar Cache Files

• Quit Calendar
• Make backup copies of the following file before deleting them
• In Finder hit CMD + SHIFT + G
• Copy and paste this path into the Go to folder window: ~/Library/Calendars/Calendar Cache
• Hit Enter
• Delete the Calendar Cache file
• In Finder hit CMD + SHIFT + G
• Copy and paste this path into the Go to folder window: ~/Library/Caches/com.apple.iCal
• Hit Enter
• Delete com.apple.iCal file (if it exists)

Try to sync. If it works viola! You’re done otherwise try next step.

#2. Clear Calendar Preference Files

• Quit Calendar
• Make backup copies of the following file before deleting them
• In Finder hit CMD + SHIFT + G
• Copy and paste this path into the Go to folder window: ~/Library/Preferences/com.apple.iCal.plist
• Hit Enter
• Delete the com.apple.iCal.plist file
• In Finder hit CMD + SHIFT + G
• Copy and paste this path into the Go to folder window: ~/Library/Preferences/com.apple.iCal.helper.plist
• Hit Enter
• Delete the com.apple.iCal.helper.plist file (if it exists)

Try to sync. If it works viola! You’re done otherwise try next step.

#3. Reset iTunes Calendar Sync

• Quit Calendar and iTunes
• Launch Terminal from /Applications/Utilities/Terminal.app
• Copy and paste the following into terminal: /System/Library/Frameworks/SyncServices.framework/Versions/A/Resources/resetsync .pl full
• Hit Enter
• Quit Terminal after the operation has completed (when Terminal returns to the command prompt with a $)

Reference: This solution was tried and tested on OS X 10.8.5, iTunes 12.1.2.27 and Calendar version 6.