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.
Send Later Requires Restart Featured
True "Send Later" functionality to schedule the time for sending an email.
TbSync Requires Restart Featured
TbSync is a central user interface to manage cloud accounts and synchronize their contact, task and calendar information with Thunderbird.
Adds the Google Calendar web interface in a new Thunderbird tab. Creating and viewing events works like in a browser (Firefox, Chrome, ...)
Provider for CalDAV & CardDAV Requires Restart
This extension adds support for CalDAV & CardDAV accounts to the Thunderbird Sync manager "TbSync". Including iCloud, Google, ownCloud, Nextcloud, Radicale and many more.
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.
Provider for Exchange ActiveSync Requires Restart
Add sync support for Exchange ActiveSync (EAS v2.5 & v14.0) accounts to TbSync
ReminderFox Requires Restart
ReminderFox displays and manages lists of reminders and tasks. ReminderFox uses easy-to-use lists with warnings/alarms to remind you of all your important appointments.
Synchronize ReminderFox with other calendars as well.
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
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.
Lightning Colors Reminder Requires Restart
Let's show the calendar color on Lightning reminders!
Adds a button to open Google Calendar in a new Tab
Todo.txt Requires Restart
Thunderbird extension for the Todo.txt application
More Snooze Requires Restart
This add allow to customize the snooze delay when snooze popup appears (lightning required).
EDS Calendar Integration Requires Restart
Integrates calendars events with Gnome clock applet
Gantt View Requires Restart
Gantt Chart view for Sunbird/Lightning
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.
Custom sync interval for Lightning Calendar Requires Restart
Allows custom synchronization intervals for remote calendars imported by Lightning Calendar (no fiddling in about:config necessary)
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.