As defined in
UIU-1907, it should be possible to automatically populate the the expiration date field based on the patron group of a user.
The offset in days should be configurable in the patron group table in settings.
This needs to be optional.
Settings > Users > patron group
The table offers another colums: "Expiration date offset (days)".
If a user creates or edits a patron group row, he can enter an integer value in a number field.
After the row is saved, the value is displayed in the table.
If the value is left empty, "-" is displayed in the table.