ThunderbirdLinux
vs
Windows CalendarWindows
Thunderbird as a Linux alternative to Windows Calendar
Updated
Our verdict
Thunderbird is a solid replacement for Windows Calendar if you also use email and want a unified inbox with calendar integration. It supports Google, Microsoft Exchange/Outlook.com, and iCloud calendars through add-ons or manual CalDAV setup. The monthly view, event creation, and reminders work well. However, it’s heavier than Windows Calendar and requires some setup for calendar syncing. It’s best for users who want email and calendar in one app and don’t mind a steeper learning curve.
- License
- MPL-2.0
- Price
- Free
- Latest version
- 159.0 (October 26, 2026)
- Rating
- —
What works the same
- Supports Google Calendar via CalDAV or provider-specific setup
- Syncs with Microsoft Exchange and Outlook.com using built-in or manual CalDAV
- Supports iCloud Calendar with manual CalDAV configuration
- Provides monthly calendar view with event creation and reminders
- Includes integrated contact management
What is different
- Thunderbird is primarily an email client with calendar as a secondary feature, making it heavier than Windows Calendar
- Requires manual setup or add-ons for iCloud and some Exchange accounts
- Lacks deep OS-level integration like Windows Calendar has in Windows
- No native Windows .ics import/export automation from Windows Calendar
- More complex interface due to additional features like news feeds and chat
Opening your Windows Calendar files
Thunderbird supports the standard iCalendar (.ics) format, which Windows Calendar also uses, so you can export events from Windows Calendar as .ics files and import them into Thunderbird. This works reliably for single events and calendars. However, recurring events or rich formatting may not always transfer perfectly. There is no direct import tool for Windows Calendar’s native files, but since both use open standards, manual .ics transfer is effective for most users.
Switching from Windows Calendar to Thunderbird, step by step
- Export your Windows Calendar data as .ics files
- Install Thunderbird on Linux with the Lightning calendar add-on if not included
- Set up your Google, Exchange, or iCloud account using Thunderbird’s account wizard
- Manually add CalDAV accounts for iCloud if needed
- Import the .ics file into Thunderbird via the calendar view
- Enable reminders and adjust event notifications in Preferences
Key features of Thunderbird
- Full IMAP and POP3 email support with multi-account management
- Built-in calendar with Lightning integration for tasks and events
- RSS and Atom news feed reader
- Chat support via Matrix, IRC, and XMPP through add-ons
- OpenPGP encryption for secure email
- Advanced message filtering and search
- Customizable interface with themes and extensions
- Contact management with LDAP and address book sync
How to install Thunderbird on Linux
flatpak install flathub org.mozilla.thunderbirdsudo apt install thunderbirdsudo apt install thunderbirdsudo dnf install thunderbirdsudo pacman -S thunderbird-i18n-frsudo zypper install MozillaThunderbirdFrequently asked questions
Can Thunderbird sync with Google Calendar?
Yes, Thunderbird can sync with Google Calendar using the built-in provider or CalDAV. You may need to enable CalDAV in Google Settings or use an add-on like Provider for Google Calendar.
Does Thunderbird support iCloud Calendar?
Yes, but not directly. You must manually add iCloud’s CalDAV server in Thunderbird’s calendar settings using your iCloud credentials and server URL.
Is Thunderbird lightweight like Windows Calendar?
No, Thunderbird is more resource-heavy because it combines email, calendar, contacts, and feeds. If you only need a calendar, consider a lighter tool like GNOME Calendar.
3 other alternatives to Windows Calendar
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