You can find some (contributed, but not very polished, which is why it isn't linked in the UI) basics here:

https://secure.phabricator.com/differential/stats/commit/

I think this has a couple of bugs, like showing @vrana as active 8 days per week, but it might give you some basics.

We've added some reporting to Maniphest too, although that stuff is a little more focused on project-level information than individuals:

https://secure.phabricator.com/maniphest/report/

I advised a company called tenXer (http://www.tenxer.com/) for a few months last year, which is building a sort of meta-product that uses a bunch of APIs (GitHub, Phabricator, other common tools) to show you information about what you spend your time on among other things -- they're still pretty early and pretty stealthy, but it's possible they'll get somewhere useful before we do. Hooking it up to Facebook Phabricator might be a challenge, though.

At least in Maniphest, we're near the limits of our ability to do stats in an ad-hoc, hacky way that doesn't involve denormalizing information into stat tables, and we'd almost certainly need to do that for some Differential stats, like "average time stuff is left open". So this might be blocked by putting together some basic aggregation infrastructure in the daemons. That said, I'm definitely interested in pursuing this more deeply sooner or later. One thing I want to do is just surface accountability stats ("@alincoln takes 10x longer to get to reviews than everyone else") as a way to possibly exert some gentle social (rather than technical) pressure on classes of problems that otherwise have undesirable, complicated technical solutions -- see discussion at https://github.com/facebook/phabricator/issues/105 and linked tasks.

@vii implemented Differential stats.

Showing me 8 active days per week wasn't a bug, I'm really that active :-).

See also T1562: Build "Facts", an ETL pipeline and charting application.

◀ Merged tasks: T3433.

Via FB / recurring request / lots of pitchfork potential when it moves forward (ref Hall of Heroes).