Lightcal

A small calendar in the Windows tray. Click the tray icon, or press a shortcut of your own, to see the month, the days that have events and today’s agenda. Connect Google, Outlook or a private ICS link if you want your events there too: Lightcal only reads them.

The same calendar and agenda in the dark theme. — The month and today’s agenda, opened from the tray. Sample events.

Runs on: Windows 11, x64
Calendars: Google Calendar, Outlook and Microsoft 365, private HTTPS ICS links. Read-only
Account: None of its own. No telemetry
Languages: English, Russian, Spanish, Japanese
Made with: Rust and Slint, no browser engine inside
Source: Open, GPL-3.0
Price: Free

Download for Windows Source on GitHub

What it shows

The month in six weeks, with week numbers and shaded weekend columns if you want them. Move by month, return with Today, or use the keyboard.
Up to three dots under a day, in the colours of its calendars.
The agenda of the chosen day: all-day events, time ranges, what is on now and how long until the next event.
In the tray, today’s date on a coral tile or in a plain outline, with the weekday or the time. The Windows clock stays as it is.
Light and dark, following Windows or the theme you choose.

An event opened in the agenda: Design review on Friday 13 November, 15:00 to 16:00, one hour, in Room 4 and video call, from the Work calendar of Google Calendar, with Copy and Open buttons. — An event opens in place: time, length, place and calendar, with Copy and, for Google and Outlook, Open in the web calendar.

Lightcal settings, the Accounts tab: a connected Google Calendar account with the Personal and Work calendars checked and Public holidays unchecked. Below: Read-only. Lightcal never changes your events. — Accounts: choose which calendars to show. The first connection shows none until you pick them.

Your calendars

You sign in to Google or Microsoft in your own browser, and Lightcal asks only for permission to read your calendars. It never creates, changes or deletes an event. A private ICS link is read over HTTPS. Sign-in tokens and ICS addresses stay on your computer, in the Windows protected store of your user account. Lightcal has no server of its own: events come straight from Google, Microsoft or the ICS host to your PC. See the Lightcal privacy policy.

Install

Each release on GitHub has a per-user installer that needs no administrator rights, a portable ZIP, and a SHA-256 checksum beside every file. Releases are signed with the maintainer’s code-signing certificate. Lightcal checks for a new version only when you ask it to, or when you turn on automatic checks.

Free and open

Lightcal is free and its source is open under the GPL-3.0. Bugs and ideas go to GitHub issues. If it is useful to you, you can sponsor its development.