Timetrack
From TUTOS
Timetracking allows the booking af timefragments to objects like projects, bugs etc. This feature will help to keep track on the efforts consumed by a topic.
A timefragment could be either a sum of time (e.g. 10 hours) or a span of time (e.g. 6:00 to 11:00).
You can get an overview (incl. sum) of all times booked on a specific object.