How does the Time Spent field differ from the Actuals field?
Time Spent is a read-only, numerical field that displays the number of hours spent on the task. The Time Spent field is populated by timesheet entries using Rally Time Tracker. It will not automatically update so the value must be manually entered on the user's Time Sheet.
Actuals, by comparison, is not related to timesheets. Temporarily show this field to record time actually spent on tasks as a way to detect lack of availability, or incorrect estimates so that they can reviewed during a retrospective. This field is hidden by default.
Updating the Estimate or To Do will not automatically update either of these fields.