Calendar and Date/Time
OBM Connector Requires Restart
OBM Lightning Calendar and addressbooks connector
Lightning Requires Restart Featured
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.
Reply Monitor Requires Restart
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.
Lightning Colors Reminder Requires Restart
Let's show the calendar color on Lightning reminders!
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.
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!
Send Later Requires Restart
True "Send Later" functionality to schedule the time for sending an email.
G-Hub Lite Requires Restart
Add Google Tabs to Thunderbird! Services supported: Voice, Calendar, Drive, Docs, Sheets, Slides, Hangouts, Plus, Photos, Contacts, News, Maps, & many more. Need Google Apps? Check out G-Hub Pro: http://www.schiffner.com/index.php/software/g-hub-pro
More Snooze Requires Restart
This add allow to customize the snooze delay when snooze popup appears (lightning required).
Purge Events Plus Requires Restart
Purge events from Sunbird and Lightning files and thereby cleanes the calendar
Show Calendar Week Requires Restart
Shows the calendar week Thunderbird/Lightning calendar's moth and multi-week view.
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.
Simple Week View Requires Restart
A simple week view for Lightning, as in the print layout.
Montezooma Requires Restart
Montezooma is a Thunderbird Addon that adds zooming functionality to windows.
NirvanaHQ Requires Restart
NirvanaHQ for Thunderbird
Todo.txt Extension Requires Restart
Thunderbird extension for the Todo.txt application
Provides button to copy the list of current reminders to the clipboard.
SanRockstar Requires Restart
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.