Saturday, August 21, 2010

How to Synchronize Outlook and Thunderbird Calendars with Google Calendar


Our goal is to synchronize the default Outlook Calendar (Windows) or the default Thunderbird/Lightning Calendar (Linux or Windows) with a Google Calender on the web, so your calendar data will automatically backed up and easily transferred to a new computer.

The first step, regardless of your desktop email client program or operating system, is to obtain a Google (that is, Gmail) account.

Create a Gmail account

You can do this here. If you have one already but do not use its calendar for any other purpose, an existing Gmail account will work fine. However, the Gmail address (for example, will be visible to meeting attendees (more on this below), even though (with the CalDAV method described here) meeting notices will neither be received at nor sent from this Gmail address. For that reason, unless you are comfortable sharing your personal Gmail address with everyone you interact with at work, you should create a new Gmail account.

Any events on a Google calendar associated with an existing personal Google account will also be synchronized with the new desktop/Google synchronized calendar. For that reason, if you already have a Google calendar for personal use, you should set up a new Google account for work to avoid confusion between work and personal events appearing on your work calendar.

Synchronizing Thunderbird/Lightning and Google Calendars

There are two methods of doing this for Thunderbird/Lightning, but only the newer one (using CalDAV) ensures that meeting invitations can continue to be sent from and received at the user's regular work email address rather than being sent from and received at the user's Gmail address. Either method requires one to set up a new desktop calendar (for example Google or Google Work) and cannot (without manually copying each event) synchronize events on an existing desktop calendar (for example, Work or Home) with the new desktop/Google calendar.

(The second method, using the Provider for Google Calendar extension, an add-on for Thunderbird, is described here under the heading Sync Mozilla Sunbird or Thunderbird with Google Calendar, but it suffers from the defect already noted - events are sent and received through the user's Gmail rather than work email address.)

Setup instructions for synchronizing Thunderbird/Lightning and Google Calendars
  1. Set up the new desktop/Google synchronized calendar associated with your existing work email address (for example, by following the Google Calendar CalDAV setup instructions
  2. Choose a color for the new calendar which allows you to easily distinguish the new calendar (Google) from your old desktop calendar (Work).
  3. Chose a name, for example, Google, for the new synchronized calendar; you can call it anything you like (for example, Google Work) so long as the name is distinct from the name of your old desktop calendar (for example, Work).
  4. On Lightning, you can display either one or both calendars by checking the boxes on the left-hand calendar pane.
  5. De-link your old Work calendar from your work email address. Right-click on "Work" on the left-hand Lightning pane (beside the check box), select properties, and opposite "E-Mail", select "None".
  6. Link your new Google calendar to your work email address. Right-click on "Google" on the left-hand Lightning pane, select properties, and opposite "E-Mail", select your work email address (for example, "". )
  7. Direct invitation responses to your work email address. By default, invitation responses will usually be received at your Gmail rather than your work email address. To fix this,  on your Google web calendar, visit "Calendar Settings", then "Calendar", "Sharing", add your work address in "Share with specific people", select "Make changes AND manage sharing", and click "Save".
The preceding steps ensure that your work email address is associated with only one calendar (your new Google calendar). Thunderbird/Lightning invitations will now appear to recipients as sent from your work address and invitations you receive at your work address will be accepted into your new Google (rather than your old Work) calendar.

Setup instructions for synchronizing Outlook and Google Calendars

We prefer Outlook's more robust and richer calendar management capabilities, but it is only available on Windows or Mac and not Linux. The method described here works for Outlook (2007 and, reportedly, for 2010), but not necessarily for the latest versions of Windows (32 and 64 bit): simply visit Google's Sync with Microsoft Outlook instructions and follow the steps described there.

Using the Google Calendar

We'll illustrate with Lightning below, but the ideas are similar for Outlook.
  1. Creating a new event. You can create a new event on Lightning (or Outlook) in the usual way and it will be immediately synchronized with your Google web calendar, and vice versa. Just be sure to select the new Google calendar when creating the event with Lightning. If you open the event, you will be listed at the top as the meeting owner on the invitation list, but your email address will be your Gmail address and not your work address. Nevertheless, if you invite an attendee, they will receive the invitation from your work address. However, if they view the event on their calendar, they will only see your Gmail address beside your name as meeting owner. To avoid confusion over your identity when sending an invitation to a participant, it is good practice to also invite yourself at your work address. That should not generate a new meeting invitation sent to your work address but, if it does, it is best to delete or decline the invitation: otherwise, a duplicate of the event will appear on your old desktop calendar, but with different event properties (you will be an event participant, not an event owner, and so unable to edit the event properties correctly).
  2. Web-created events. If you create an event your Google calendar on the web, rather than through your desktop, but the event does not then appear reflected on your desktop calendar, right-click on "Google" on the left-hand Lightning pane, and select "Reload Remote Calendars".
  3. Receiving invitations and your Gmail inbox. You may see meeting invitations or updates appear in your Gmail inbox duplicating those appearing in your work email inbox. You should ignore or delete the Gmail inbox invitations, as you will be processing them from your work email inbox.
  4. Receiving meeting updates. The delinking of your old Work calendar from your work email address will prevent updates to events in your old Work calendar. A meeting update should be automatically added to the new Google calendar when you accept it (check), while event cancellations can be handled by simply by deleting the event from the old work calendar.
  5. Sending meeting updates. Meeting updates are not always consistently handled by Lightning (or across different programs or platforms). It may be safer to cancel the old event and send a new event invitation with the updated information.
  6. Managing events on the synchronized calendar. You can edit events on the Google calendar in the usual way from within Lightning or from Google on the web (care should be exercised with updates), but you should use Lightning unless there is a reason to edit the event on the web calendar (for example, when traveling and away from your usual desktop).
  7. Transitioning one-time events from your old desktop calendar. It is possible manually copy each event on your old desktop calendar to the new synchronized calendar. However, that can create more confusion than it's worth, as results may be unpredictable (for example, meeting invitations may be resent). It is better to simply let one-time events on the old calendar expire. If you still wish to transition all events on the old calendar to the new calendar, then it is best to manually recreate each event on the new calendar and delete it on the old calendar, informing other participants if needed. When all such events have expired and a historical calendar record is no longer needed, the old calendar can be deleted entirely from your desktop. Deleting the old calendar avoids possible confusion when creating a new event if the Google calendar is not selected (if possible, make this the default calendar).
  8. Transitioning recurring events from the old to the new calendar. These will have to be manually deleted from the old desktop calendar and recreated on the new synchronized calendar. If a recurring event involves a corporate client (unlikely), then he or she should also be alerted by email and asked to accept the new event, though it may appear as a duplicate, and manually delete the old one if necessary.
  9. Managing the same Google calendar from more than one desktop. You can synchronize your Google web calendar with your desktop work calendar at more than one computer (for example, a desktop and a laptop). Simply repeat the setup instructions for the second computer.
  10. Add US (and other) public holidays. Visit the Mozilla holiday calendar page to subscribe to a separate holiday calendar.
  11. Check events when they are created, updated, or canceled. Technology is not perfect and it is unwise to assume the calendar is working without inspecting the events each time you create them and periodically checking that they are mirrored on the version of your calendar on the web. This is especially the case when different calendar programs are involved (Mozilla, Outlook, Lotus Notes, Google, Yahoo, Hotmail, Blackberry, and others), not all of which use identical calendar formats.
Other synchronization options

For Outlook, Microsoft provides its free Windows Live service (including Hotmail, Contacts, Calendar and To-Do List), which allows the user to publish her Outlook calendar. Follow the Microsoft instructions and the MSDN blog for tips.

Questions or Comments

Both are welcome. Visit the Mozilla Calendar Project for additional information.