Windows theme switching, automated without a background app.

The problem
Automatic light and dark switching is useful, but the tools that do it usually leave a tray icon or a background process running all day for a job that takes a fraction of a second twice a day.
What I did
I built AutoDark in .NET with a single ON/OFF button. It works out sunrise and sunset from Windows location or coordinates you enter, then hands the timing to Windows Task Scheduler. The app itself exits completely when you close it. Turning it OFF removes the task and restores your earlier theme settings.
The result
A Windows installer that needs no administrator rights, with no account, no telemetry and no resident process. It ships with built-in self-tests and a read-only Task Scheduler check, and the code is open source under the MIT license.

Check it yourself