Add a Powerful Calendar to Thunderbird with Lightning

Mozilla’s Thunderbird desktop email client doesn’t have a calendar out of the box. The Lightning calendar addon gives Outlook a run for its money, and it’s all free.

While there aren’t many full-feature email and calendar alternatives to Microsoft Outlook, Mozilla’s Thunderbird comes close, and it’s free. The thing is, Thunderbird doesn’t have a calendar by default.  Lightning is a free add-on that brings in a full-featured calendar and task system, similar to what you would find in Outlook. Lightning can pull down and sync with Google Calendar, Exchange, and other calendars. Follow along as we take a quick tour of it.

Lightning Calendar for Thunderbird

Lighting brings two new tabs to Thunderbird. A Calendar tab and a Tasks tab. The two are interchangeable, especially since any task can be converted to an event and vice versa. The calendar view also shows events, dates, and multiple different views of as many calendars as you need to add.

lightning calendar tab

Adding events to the calendar is easy. The New Event window offers empty spaces for all of the details, times, reminders, invitations, and any other info you might need to attach to it. You can also choose whether to make events public or private (depending on where your calendar syncs from).

add event

The Task pane is less cluttered and simple, and you’ll notice that the sidebar now contains calendar Events. Adding new tasks involves typing them in and then press the New Task button.

lightning task tab

Unlike calendar events, tasks can have priorities, progress, and completion mark. Tasks can also be postponed or transferred to a different calendar with ease.

postpone tasks

Reminders can be set to go off at any duration desired before an event or when dealing with tasks if the task isn’t completed. These reminders can be snoozed for a specific amount of minutes like an alarm clock, or they can be dismissed.

event and task reminders

The calendar offers a place to change default settings for reminders and other settings within the Options tab. This is particularly useful if you want Tasks to have an alarm attached automatically each time one is created.

calendar reminder settings

Overall Analysis

When you combine all of the powerful features found in Thunderbird’s Lighting add-on and its free price tag, it gives Microsoft Outlook solid competition. The calendar is effective, intuitive, and it doesn’t hog system resources on the computer it is running on. The main downside is that Lightning doesn’t work with the beta channel of Thunderbird, so you won’t be able to test the latest and greatest version with it. But if you’re happy running the most recent stable release, Lightning maybe a calendar system worth checking out.



  1. G. Lange

    March 15, 2013 at 10:57 am

    I would agree with you…Thunderbird and Lightning are indeed a great piece of software.

    However…if you depend on a task manager (like I do) and really need it to be in sync with a Android smartphone, tablet, etc…then you might want to save yourself some grief and try something else. I’ve been researching and testing various “solutions” for more than three years. To date, there is still only one or two actually methods of syncing the Lightning Tasks with an application on the phone or other device, no one seems to be working on a sync with Lightning.

    The solutions I mentioned require one or more third and fourth party account or product and were not simple. For example (and this is from the support site for one of these products)

    Thunderbird/Lightning connected to a SyncML server (paid account).
    The SyncML connected to a Web-based Task Management app (monthly fee of course).
    Web app sync to an Android app, but only their proprietary app (which wasn’t great)

    I love Thunderbird and really want to use it all again…but after the first year with nothing…I was disappointed. Second year, I was getting miffed. Third year…want revenge. Now…I have officially given up and gone back to a plan cellphone and a 10 year old Palm Pilot that syncs great…plus my old paper planner. I’m back to happy

  2. Sean S.

    April 14, 2022 at 9:02 pm

    Great article and helpful, except a little out of date, for the simple reason that as of Thunderbird 78 Lightning Calendar and Tasks are completely integrated into the base Thunderbird application, so there’s no need to install it separately. In other words, Thunderbird now *does* come with a calendar/tasks.

    • Ben Stockton

      April 25, 2022 at 2:50 am

      Thanks for the tip, Sean! We’ll look to get this article updated shortly.

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