To have a fully data aware component it would be advisable to have also RangeFrom and RangeTo data binded.
We will consider this for a future update.
If we suppose that the dbaware version is based on a master-detail schema the detail table should supply the items informations (as it is now) and the master table should provide the boundary conditions. Another way is to calculate Min and Max date of the detail table but this is a dynamic way I cannot figure how to implement unless assignin the SQL command to a property.
The db-aware version is not based on the assumption that a master-detail schema is used. We consider this as too restrictive as it should be possible to use the DBSmoothList also with a single table. It is then currently of course the responsibility of the application code to set the range according to the desired timespan.