add logic to define start and end points for situation where desired …

…date range is contained by xarray dataset to crop_date_range

src/preprocessor.py

@@ -881,6 +881,10 @@ def crop_date_range(self, case_date_range: util.DateRange, xr_ds, time_coord) ->
         # dataset overlaps user-specified date range end
         elif date_range_cf_start < ds_start <= date_range_cf_end <= ds_end:
             new_xr_ds = xr_ds.sel({time_coord.name: slice(ds_start, date_range_cf_end)})
+        # dataset contains all of requested date range
+        elif date_range_cf_start>=ds_start and date_range_cf_end<=ds_end:
+            new_xr_ds = xr_ds.sel({time_coord.name: slice(date_range_cf_start, date_range_cf_end)})
+
         return new_xr_ds
 
     def check_group_daterange(self, df: pd.DataFrame, date_range: util.DateRange,