Currently if you create a project it automatically adjusts the timeframe so that it takes the date of the first and last worklog in the issues that belong to the project.
After that if new worklogs are added the timeframe automatically adjusts. If a user edits the timeframe manually this functionality is lost.
It has been proposed to implement a “clear” button that removes any user-specified timeframe and goes back to the default “Calculated” timeframe allowing for the automatic adjustments.
|Tempo Products||Cost Tracker for Tempo Timesheets|