I use my own, simple CLI tool* (not only to track working hours, but also to track open source or hobby activiets). For many years I used Toggl, which is great

I use my own, simple CLI tool* (not only to track working hours, but also to track open source or hobby activiets). For many years I used Toggl, which is great and powerful - I just needed something that works offline. [*] https://github.com/WojciechMula/timetracker https://github.com/WojciechMula/timetracker