Punch is a time-tracking add-on for todo.txt - a command line to-do list list utility. Punch works alongside the todo.txt script files popularized by Life Hacker and todotxt.org. All time tracking info is kept in a separate file, so no harm is done to the todo.txt system. It does use your todo.cfg file and todo.txt file to streamline time tracking.

Punch uses a punch clock metaphor to track where you are spending your time.

For example, if your to-do list looks like this...

$ t ls
02 Call Steve about subcontracting gig @Steve +Acme
03 Prepare invoices for February
01 Prepare project proposal for Acme +Acme
--
TODO: 3 tasks in C:/cygwin/home/Keith/todo/todo.txt.

...you would start keeping time for a given task like this:

$ punch in 1
Start timer on: Prepare project proposal for Acme +Acme

When switching your focus, simply punch in again:

$ punch in 2
Stop timer on: Prepare project proposal for Acme +Acme
Start timer on: Call Steve about subcontracting gig @Steve +Acme

And when finished, punch out:

$ punch out
Stop timer on: Call Steve about subcontracting gig @Steve +Acme

To get a report of what you have worked on, use the report command. Time spent on tasks is summed up daily.

$ punch rep
2009-03-12:
        Prepare project proposal for Acme +Acme (22 minutes)
2009-03-14:
        Call Steve about subcontracting gig @Steve +Acme (0 minutes)
        Prepare invoices for February (31 minutes)
        Prepare project proposal for Acme +Acme (1 minutes)
2009-03-16:
        Prepare project proposal for Acme +Acme (1 minutes)

Punch requires Python. Punch is a work in progress. Feel free to suggest enhancements you'd like to see.