Stim is a simple application for tracking time spent on various tasks. Stim records context switches and session stops and provides a reporting mechanism. While a simple command-line utility, Stim can integrate with the user environment and desktop tools to provide a fairly useful time clock.
Stim records to a basic log file where records can be easily added, modified, or removed. Reports can be generated for a particular time period with some flexibilty in reporting. See man stim for an overview.
autoconf && ./configure && make && sudo make install