Calendar and Date/Time


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)
5,886,184 users

Send Later Requires Restart

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

Rated 5 out of 5 stars (79)
64,949 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)
26,881 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)
16,039 users

Lightning Colors Reminder Requires Restart

Let's show the calendar color on Lightning reminders!

Rated 5 out of 5 stars (1)
4,048 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)
3,609 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)
2,282 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)
1,512 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)
1,238 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)
1,208 users

LCD Clock Requires Restart

displays a LCD Clock in your Toolbar

Rated 5 out of 5 stars (7)
1,006 users

OBM Connector Requires Restart

OBM Lightning Calendar and addressbooks connector

Not yet rated
989 users

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!

Rated 4 out of 5 stars (1)
983 users

Montezooma Requires Restart

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

Rated 3 out of 5 stars (8)
822 users

Simple Week View Requires Restart

A simple week view for Lightning, as in the print layout.

Rated 3 out of 5 stars (3)
589 users

Todo.txt Extension Requires Restart

Thunderbird extension for the Todo.txt application

Rated 4 out of 5 stars (5)
508 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)
463 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)
437 users

Macro Template

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

Rated 5 out of 5 stars (1)
375 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)
375 users