We looked at doing things like logging git commit frequency to try and provide realistic estimates to users of their time that they could then confirm or alter. Realistically, with the diversity of talent we have here (both technical and non-technical) and the time it would take to do well, it didn't really seem too practical.

It would be awesome if WakaTime and others provided some way of interfacing with an API, so that individuals could track time in a way that made sense for them while reporting in a relatively consistent standard to a central system used for accounting and billing.