Calendar and Date/Time


Send Later Requires Restart

True "Send Later" functionality to schedule the time for sending an email.

Rated 5 out of 5 stars (79)
64,942 users


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.

Rated 5 out of 5 stars (17)
16,141 users

Show Calendar Week Requires Restart

Shows the calendar week Thunderbird/Lightning calendar's moth and multi-week view.

Rated 5 out of 5 stars (6)
2,265 users

LCD Clock Requires Restart

displays a LCD Clock in your Toolbar

Rated 5 out of 5 stars (7)
1,098 users

MultiBirthdaysReminder Requires Restart

This addon is now integrated into the new address book CardBook and thus it is no longer maintained

Rated 5 out of 5 stars (6)
455 users

More Snooze Requires Restart

This add allow to customize the snooze delay when snooze popup appears (lightning required).

Rated 5 out of 5 stars (5)
1,232 users

SanRockstar Requires Restart


Rated 5 out of 5 stars (3)
36 users

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.

Rated 4 out of 5 stars (20)
1,514 users

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.

Rated 4 out of 5 stars (8)
27,010 users

MiniWebView Sidebar Requires Restart

Sidebar that shows a single web page. This allows Thunderbird to be augmented with any user-supplied or third-party web page. The screenshot shows an example - I use my own custom web page to present my Google Calendar in my preferred format.

Rated 5 out of 5 stars (4)
69 users

EDS Calendar Integration Requires Restart

Integrates calendars events with Gnome clock applet

Plugin may hang on Fedora.
As a workaround uninstall evolution-ews.

Rated 4 out of 5 stars (8)
442 users

StormCows Requires Restart

Allows two-way access between Remember The Milk and calendar events or todo items.

Rated 4 out of 5 stars (10)
367 users

Todo.txt Extension Requires Restart

Thunderbird extension for the Todo.txt application

Rated 4 out of 5 stars (5)
532 users

Purge Events Plus Requires Restart

Purge events from Sunbird and Lightning files and thereby cleanes the calendar

Rated 4 out of 5 stars (9)
1,213 users

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.

Rated 3 out of 5 stars (1,922)
5,855,568 users

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:

Rated 4 out of 5 stars (3)
3,607 users

Montezooma Requires Restart

Montezooma is a Thunderbird Addon that adds zooming functionality to windows.

Rated 3 out of 5 stars (8)
839 users

Macro Template

Macro Template is to replace mail templates with macros for date formatting.

Rated 5 out of 5 stars (1)
385 users

Task Me (activity logger) Requires Restart

Activity logger (sampled task monitoring) which uses calendar to store user's activities.

It periodically displays window with textbox where user can put description of currently performed tasks. The description is saved in a calendar.

Rated 4 out of 5 stars (2)
78 users

Lightning Colors Reminder Requires Restart

Let's show the calendar color on Lightning reminders!

Rated 5 out of 5 stars (1)
4,068 users