Calendar and Date/Time
Lightning Requires Restart
Organize your schedule and life's important events in a calendar that's fully integrated with your Thunderbird email. Manage multiple calendars, create your daily to do list, invite friends to events, and subscribe to public calendars.
Provider for CalDAV & CardDAV Requires Restart
This extension adds support for CalDAV & CardDAV accounts to the Thunderbird Sync manager "TbSync".
Lightning Invitation Notifier Requires Restart
This extension is an extension to Mozilla Lightning for Thunderbird.
It shows a toast message and opens the invitations window when an invitation arrives.
TbSync Requires Restart Featured
TbSync is a central user interface to manage cloud accounts and synchronize their contact, task and calendar information with Thunderbird.
Provider for Exchange ActiveSync Requires Restart
Add sync support for Exchange ActiveSync (EAS v2.5 & v14.0) accounts to TbSync
Add Microsoft Office 365 Tabs to Thunderbird! Services supported by M-Hub Lite: Calendar, People, OneDrive, Word, Excel, PowerPoint, & Bing. Need business or enterprise support? Get M-Hub Pro: https://www.schiffner.com/index.php/software/m-hub-pro
Add Google Tabs to Thunderbird! Services supported by G-Hub Lite: Calendar, Contacts, Drive, Docs, Sheets, Slides, Maps, Search, & Voice. Need G Suite / Google Apps support? Check out G-Hub Pro: https://www.schiffner.com/index.php/software/g-hub-pro
Send Later Requires Restart Featured
True "Send Later" functionality to schedule the time for sending an email.
EDS Calendar Integration Requires Restart
Integrates calendars events with Gnome clock applet
Lightning Calendar Tabs Requires Restart
Displays tabs which allows quick navigation between time periods in Lightning calendar. All views of calendar are supported. Color of tab texts can be adjusted.
Enhanced Date Formatter Requires Restart
Configure the 'Date' and 'Received' columns and displayed date in the message pane using custom formats. You can even use different date formats for emails with today's date, yesterday's date, dates in the last week, or dates older than a week.
Todo.txt Requires Restart
Thunderbird extension for the Todo.txt application
Purge Events Plus Requires Restart
Purge events from Sunbird and Lightning files and thereby cleanes the calendar
lightningWeather Requires Restart
LightningWeather shows the weather forecast in the background of the calendar so you can easily coordinate your activities with the weather.
More Snooze Requires Restart
This add allow to customize the snooze delay when snooze popup appears (lightning required).
Adds the Google Calendar web interface in a new Thunderbird tab. Creating and viewing events works like in a browser (Firefox, Chrome, ...)
Show Outlook Appointments (vcal / ics) Requires Restart
An extension to show embedded Outlook calendar (vcal / ics) parts.
Thunderbird doesn't show calendar parts from Outlook appointment emails. This addon adds a button to download the embedded appointment as ICS to import it into another calendar.
NirvanaHQ Requires Restart
NirvanaHQ for Thunderbird
Zonio Freebusy for Lightning Requires Restart
Finds when are people available for a meeting or event via Zonio Freebusy service. Displays freebusy blocks instantly in Invite Attendees window while attendees are being added. Works with both local calendar storage or any calendar provider.
Reply Monitor Requires Restart
**This is NOT COMPATIBLE with Thunderbird 31 or newer versions**
Keep track of your emails and replies (Lightning is required).
Note: the name of this add-on has been changed to Reply Monitor because the previous name is a registered trademark.