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
True "Send Later" functionality to schedule the time for sending an email.
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.
ReminderFox displays and manages lists of reminders and ToDo's. ReminderFox makes sure you remember all of your important dates via easy-to-use lists, alerts, and alarms, right in your browser without the need for a separate calendar program.
TbSync is a central user interface to manage cloud accounts and synchronize their contact, task and calendar information with Thunderbird.
Add sync support for Exchange ActiveSync (EAS v2.5 & v14.0) accounts to TbSync
Lightning Colors Reminder Requires Restart
Let's show the calendar color on Lightning reminders!
G-Hub Lite Requires Restart
Add Google Tabs to Thunderbird! Google services supported by G-Hub Lite: Calendar, Contacts, Drive, Docs, Sheets, Slides, Maps, Search, & Voice. Need G Suite / Google Apps? Check out G-Hub Pro: https://www.schiffner.com/index.php/software/g-hub-pro
Gantt View Requires Restart
Gantt Chart view for Sunbird/Lightning
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.
Open Google Calendar Requires Restart
Adds the Google Calendar web interface in a new Thunderbird tab. Creating and viewing events works like in a browser (Firefox, Chrome, ...)
lightningWeather Requires Restart
LightningWeather shows the weather forecast in the background of the calendar so you can easily coordinate your activities with the weather.
Lightning Reminder Left Buttons Requires Restart
Tired to mistakenly press that "Dismiss All" button? Move the Lightining Reminder "Snooze all for" and "Dismiss All" buttons to the LEFT!
... and from version 2.0 you can keep them on the RIGHT, but swapped!
AdvancedTasks Requires Restart
Thunderbirds Lightning Extension: Allows the use of Markdown in Task descriptions and renders them as HTML in the TaskView.
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
Plugin may hang on Fedora.
As a workaround uninstall evolution-ews.
OBM Connector Requires Restart
OBM Lightning Calendar and addressbooks connector
The 'NoiaButtons' add-on offers cartoonish toolbar button icons (known from Noia themes) for default theme and lightweight themes. Further more lite silver and dark versions of Noia themes are included.
Todo.txt Requires Restart
Thunderbird extension for the Todo.txt application