Automatic and invisible time tracking – open-sourced – privacy focused

I've been looking for a way to answer questions like:

- "How long did I REALLY waste on Reddit/Hacker news yesterday?" (39 minutes, not as bad as I thought)

- "How long do I spend in front of my computer on average?" (12 hours...)

- "Which project has taken up the most time this week?" (20 hours on XYZ...)

This answers all of these questions and more; without any input from me.

The best part is that the data is kept locally.

There is also a robust API so you can develop your own dashboards or programs from the data.