code: def items_between(start_date, end_date, opts={})
        items do |obj|
          obj.restriction = { :and =>
            [
              {:is_greater_than_or_equal_to =>
                [
                  {:field_uRI => {:field_uRI=>'item:DateTimeReceived'}},
                  {:field_uRI_or_constant=>{:constant => {:value =>start_date}}}
                ]
              },
              {:is_less_than_or_equal_to =>
                [
                  {:field_uRI => {:field_uRI=>'item:DateTimeReceived'}},
                  {:field_uRI_or_constant=>{:constant => {:value =>end_date}}}
                ]
              }
            ]
          }
        end
      end
docs: Fetch items between a given time period
   @param [DateTime] start_date the time to start fetching Items from
   @param [DateTime] end_date the time to stop fetching Items from