By default, historical information is not kept on directories/packages and therefore the timeline has no values to display below the project or module level. This can be changed by logging in as an a System administrator, going to Settings > General Settings > Database Cleaner and setting the Clean history data of directories/packages property to false. This Note that this will increase the volume of data to be stored in the database.
A default Time Time Machine dashboard comes out-of-the-box. This is a combination of Timeline and History Table widgets:
What are Tendencies?
It is possible to configure the tendencies by logging in as an a System administrator and going to Settings > General Settings > Differential Views. To configure the number of days used to compute tendencies, set the Tendency period property to the desired number of days. Default is 30.
Whatever the reason (wrong quality profile, issue with analysis, etc.), it is possible to remove a snapshot to polish the Time Machine widgets. Note that the last snapshot can never be deleted.
Deleting a snapshot is a 2-step process:
At project level, go to Configuration > History.
For every snapshot, it is possible to manually:
These settings can be changed at Settings > General Settings > Database Cleaner.