or
<GroupByExpressions> <telerik:GridGroupByExpression> <SelectFields> <telerik:GridGroupByField FieldAlias=" " FieldName="OFIdate" FormatString="{0:D}" HeaderValueSeparator=""></telerik:GridGroupByField> </SelectFields> <GroupByFields> <telerik:GridGroupByField FieldName="OFIdate" SortOrder="Ascending"></telerik:GridGroupByField> </GroupByFields> </telerik:GridGroupByExpression> </GroupByExpressions>