Diagnosis
For the research frequency you have selected 'periodic', however, noentry was made for the range.

System Response
Since, a range entry is necessary for periodic researches, this wasautomatically set to "monthly".

Procedure
You can adopt the setting made by the system, or replace it with yourown values. To set the range yourself, switch to the tab page'information requirements' and make the desired setting in the view'delivery parameter'.