Use Dropbox to Sync iCal with Older Versions of OS X

You can sync your Mac's calendar app by storing its calendar files in the cloud

iCal icon from OS X Lion
Now that we have moved the Calendars folder, we need to tell iCal and the Finder its new location. We do this by creating a symbolic link from the old location to the new one. Courtesy of Apple

iCal syncing is one of the handy features available in iCloud, Apple's cloud-based service. It was also available in MobileMe, Apple's previous cloud service. By syncing your calendars, you were assured that any Mac you used on a regular basis would always have all of your calendar events available to you. This is handy if you use multiple Macs at home or in the office, but it's especially handy if you take a mobile Mac on the road. When you update your iCal app on one Mac, the new entries are available on all of your Macs.

With the advent of iCloud, you can continue iCal syncing just by upgrading to the new service. But if you have an older Mac, or you don't want to update your OS to Lion or later (the minimum version of OS X required to run iCloud), then you may think you're out of luck.

Well, you're not. With a few minutes of your time and Apple's Terminal app, you can continue to sync iCal with multiple Macs.

What You Need for iCal Syncing with Dropbox

  • Two or more Macs.
  • OS X Leopard (10.5.x) or later. I believe these instructions will work for earlier versions of OS X, but I haven't been able to test them. If you decide to try this with an earlier version of OS X, please let us know how it goes.
  • A cloud-based storage service. The instructions in this guide are for Dropbox. Other cloud services may work as well, but we've only tested Dropbox.
  • A few minutes for each Mac you wish to sync.

Let's Get Started

  1. Install Dropbox, if you're not already using it. You can find instructions in the Setting Up Dropbox for the Mac guide.
  2. Open a Finder window and navigate to your home folder/Library. Replace "home folder" with your user name. For example, if your username is tnelson, the full path would be /Users/tnelson/Library. You can also find the Library folder by clicking on your username in a Finder sidebar.
  3. Apple hid the user's Library folder in OS X Lion and later. You can make it visible with these tricks: OS X Lion Is Hiding Your Library Folder.
  4. Once you have the Library folder open in a Finder window, right-click the Calendars folder and select Duplicate from the pop-up menu.
  5. The Finder will create a duplicate of the Calendars folder and name it "Calendars copy." We created the duplicate to serve as a backup, since the next steps will remove the Calendars folder from your Mac. If something goes wrong, we can rename the "Calendars copy" folder back to Calendars, and be right back where we started.
  1. In another Finder window, open your Dropbox folder.
  2. Drag the Calendars folder to the Dropbox folder.
  3. Wait for the Dropbox service to finish copying the data to the cloud. You'll know when it's finished by the green check mark that appears in the Calendars folder icon in the Dropbox folder.
  4. Now that we have moved the Calendars folder, we need to tell iCal and the Finder its new location. We do this by creating a symbolic link from the old location to the new one.
  5. Launch Terminal, located at /Applications/Utilities/.
  6. Enter the following command into Terminal:
    1. ln -s ~/Dropbox/Calendars/ ~/Library/Calendars
  7. Hit Enter or Return to execute the Terminal command.
  8. You can check that the symbolic link was created correctly by launching iCal. All of your appointments and events should still be listed in the app.

Syncing Multiple Macs

Now that we have your main Mac synced with the Calendars folder in Dropbox, it's time to get the rest of your Macs up to speed by telling them where to look for the Calendars folder.

To do this, we're going to repeat all of the above steps except one. We don't want to drag the Calendars folders on the remaining Macs to the Dropbox folder; instead, we want to delete the Calendars folders on those Macs. Don't worry; we'll still create a duplicate of each folder first.

So, the process should look like this:

  • Perform steps 1 through 4.
  • Drag the Calendars folder to the trash.
  • Perform steps 9 through 13.
  • That's it; all of your iCal apps are now synced.

One additional note: Because you're syncing all of your Macs against one Calendars folder, you may see a message about an incorrect iCal account password, or a server error. This can happen when the source Calendars folder had data for an account that isn't present on one or more of your other Macs. The solution is to update the account information for the iCal app on each Mac, to make sure they're all the same. To edit the Account information, launch iCal and select Preferences from the iCal menu. Click the Accounts icon, and add the missing account(s).

Removing iCal Syncing With Dropbox

At some point, you may decide that upgrading to a version of OS X that supports iCloud and all of its syncing capabilities may be a better choice than trying to use Dropbox to sync your calendar data. This is especially true when using versions of OS X newer than OS X Mountain Lion, which are integrated with iCloud and make using alternate syncing services much more difficult.

Removing iCal syncing is really as easy as removing the symbolic link you created above and replacing it with a current copy of your iCal folder stored on Dropbox.

Start by making a backup of the Calendars folder located on your Dropbox account. The Calendars folder holds all your current iCal data, and it is this information we want to restore to your Mac. You can create a backup by just copying the folder to your Mac’s desktop. Once that step is completed, let’s get going:

Close iCal on all Macs that you have set up to sync calendar data through Dropbox.

To return your Mac to using a local copy of the calendar data instead of the one on Dropbox, we're going to delete the symbolic link you created in step 11, above.

Open a Finder window and navigate to ~/Library/Application Support.

OS X Lion and later versions of OS X hide the user's Library folder; this guide will show you how to access the hidden Library location: OS X Is Hiding Your Library Folder.

Once you have arrived at ~/Library/Application Support, scroll through the list until you find Calendars. This is the link we'll be deleting.

In another Finder window, open your Dropbox folder and locate the folder named Calendars.

Right-click the Calendars folder on Dropbox, and select Copy ‘Calendars’ from the pop-up menu.

Return to the Finder window you have open on ~/Library/ Application Support. Right-click in an empty area of the window, and select Paste Item from the pop-up menu. If you have problems finding an empty spot, try changing to the Icon view in the Finder’s View menu.

You'll be asked if you wish to replace the existing Calendars. Click OK to replace the symbolic link with the actual Calendars folder.

You can now launch iCal to confirm that your contacts are all intact and current.

You can repeat the process for any additional Mac you have synced to the Dropbox Calendars folder.

Once you have restored all of the Calendars folders to all affected Macs, you can delete the Dropbox version of the Calendars folder.