Timewarrior automatically tracks your time using [start][1] and [stop][2] commands. It also works like a Stopwatch[3], no start command needed.

[1] https://timewarrior.net/docs/timew-start.1.html

[2] https://timewarrior.net/docs/timew-stop.1.html

[3] https://timewarrior.net/docs/stopwatch.html