Though this will catch the obvious cases where you should be billing but aren't while actively writing code, what about doing research or reading? Or code reviews? In a sufficiently complicated codebase, it might be the case that you're reading and thinking a lot longer than you're actively writing…<p>It is pretty neat to see the time spent actively writing each commit, though, and the file monitoring provides a better check than just looking at the delta between timestamps, so bravo for that!