How to Export Calendars from Thunderbird to Outlook?

Calendars in email clients, such as Thunderbird and Outlook, allow users to schedule meetings and appointments, or manage upcoming events. Therefore, when moving from Mozilla Thunderbird to MS Outlook, it becomes vital to transfer calendars also. In this article, we will explain a manual method and a specialized MBOX to PST converter software to help you export calendars from Thunderbird to Outlook.

Methods to Export Calendars from Thunderbird to Outlook

Here, we’ll mention two methods that you can use to transfer your calendars to Outlook from Thunderbird.

Method 1: Save Thunderbird Calendars in ICS Files

Outlook supports the iCalendar (ICS) file format for importing calendar items. Therefore, you can export your calendar from Thunderbird to ICS file and then import it into Outlook. Here’s the stepwise process:

Step 1: Export Thunderbird Calendar to ICS File

First, export the required calendars from Thunderbird to ICS files by following these steps.

• Launch Thunderbird on your PC.
• Click on the Calendar icon on the left.

• You will see all your calendars listed in the left pane.
• Select a calendar and right-click on it.
• Click on Export Calendar.

• The Export window will open. Choose the destination folder. You can also provide a different name.
• Click on Save. This will save the selected calendar in ICS file format.

You can repeat the above process to export other calendars to ICS files.

Step 2: Import iCalendar (ICS) Files into Outlook

Now, you can import the ICS files into Outlook by following these steps:

• Launch Outlook. Click on File in the ribbon.
• Click on Open & Export > Import/Export.

• Select the Import an iCalendar (.ics) or vCalendar file (.vcs) option in the Import and Export Wizard. Click Next.

• Locate and select the ICS file saved on your PC.
• Click on Open.

• You will get a prompt to open the calendar file as a new calendar or import its items into an existing calendar. Select an option as per your requirement. Here, we’ll be selecting Open as New.

• This will open the Thunderbird calendar in Outlook.

Repeat the above steps to import other ICS files.

Limitations of the above Manual Method

Listed below are some limitations of manually exporting calendars from Thunderbird to Outlook:

• It is a slow and repetitive process as you can only export one calendar from Thunderbird at once. Similarly, while importing in Outlook, you can only select one ICS file in one instance.
• There is a chance of human error while exporting a large number of Thunderbird calendars.
• In case there is a network sync issue, Thunderbird may not fully download events. So, exporting a remote calendar (CalDAV), may result in an incomplete ICS file with missing events.

Note: Thunderbird no longer lets you save calendars as CSV files since the Thunderbird v102 update.

Method 2: Use a Dedicated MBOX to PST Converter

If you are migrating from Thunderbird to Outlook, you may not only need to export calendars but also other mailbox items, like emails, contacts, tasks, etc. For this, you can use Stellar Converter for MBOX - an advanced MBOX to PST converter tool that lets you convert Thunderbird mail items, including calendars, to Outlook-importable PST format.

The tool retains the original mailbox structure and folder hierarchy in the resulting PST file. You can also save specific items from your MBOX file as MSG or EML files. It supports MBOX files of 17+ email clients, like Mozilla Thunderbird, Gmail (Google Takeout), Apple Mail, Eudora, and more.

Follow the step-by-step process given below to export the calendar from Thunderbird to Outlook using Stellar Converter for MBOX.

Part 1: Convert Thunderbird MBOX to PST File

If you have Mozilla Thunderbird installed and configured on your system, you can use Stellar Converter for MBOX to select the identity folder present on your system to save calendar items as a PST file.

Note: In case you have installed Thunderbird on another computer, you’ll need to first, export the user profile using the ImportExportTools NG add-on. Then, move it to the PC where Stellar Converter for MBOX is installed.

Here is how to use this software:

• Download Stellar Converter for MBOX from its official website. Install it.
• When you launch the software, the Select MBOX window will appear.
• Select Thunderbird from the Email Client dropdown menu.
• The software will automatically select the Thunderbird identity folder present at the default location.

Note: Click on Select Identity to select the Thunderbird profile folder that you have exported and stored at another location on your system/connected external storage.

• Now, click Convert. This will begin scanning the selected MBOX file.

• Once the scan is complete, the software will list all the mailbox items. Click on the Calendar button in the Navigation Pane to open Calendar items.

• Select a calendar to see its preview.
• Click on the Mail icon to go back to the navigation tree.
• Select the calendars that you want to export.

• Then, click on Save Converted File.
• It will open the Save As window. Select the Save as PST option to save the selected Thunderbird calendar in PST file format.
• Click Next to proceed.

• It will show the Choose Destination box. Click on Browse to select the destination folder and click on Save.

• The software will convert and save the selected Thunderbird calendar(s) as PST file. It will show a completion dialog box. Click OK to close it.

Note: You can also use Stellar’s free online MBOX to PST converter service to quickly convert a single MBOX file of size ≤100MB to PST without downloading any additional software.

Part 2: Import the Converted PST file into Outlook

After successfully saving the Thunderbird calendar in PST file, use Outlook’s Import/Export wizard to import it into Outlook. Follow the steps below:

• Launch Outlook on your PC and click on File.
• Click on Open & Export > Import/Export.
• Select the Import from another program or file option. Click Next.

• Select Outlook Data File (.pst). Again, click on Next.

• Locate and select the PST file, select it, and click OK.

• Click on the Calendar icon at the bottom of the Navigation Pane to open the calendars.
• You will find the calendar that you have exported from Thunderbird under the My Calendars section in the left pane.

Conclusion

When moving from the Thunderbird email client to Outlook, you need to also export calendars, apart from emails and other items. To export calendar from Thunderbird to Outlook, a manual way is to save the calendars as ICS files and then import them into Outlook.

A simple way to export Thunderbird calendars to Outlook is by using Stellar Converter for MBOX – a powerful MBOX to PST converter software. You can use it to save calendars and other mailbox items such as emails and contacts from the Thunderbird identity folder to PST format. You can also use this software to directly export mailbox data to an Outlook profile or existing PST file with ease.