The incorrect Gradebook dates occur when the Gradebooks are created before the correct term dates have been set up or if changes have been made to the term dates in School Options.  

To correct the dates the teacher can navigate to the Edit Gradebook tab under Manage Gradebook and uncheck the term that it is associated with the Gradebook, then click Save.  Then associate the Gradebook to the desired term and click Save.  In this case, the teacher can ignore the red error messages during the process.  Click Save.  The process can be run on each Gradebook to update Gradebooks with incorrect term dates.