If hierarchy is ...-Months-Days

SELECT

NON EMPTY { [Measures].[Sales Amount] } ON COLUMNS,

NON EMPTY { filter([Date].[Calendar].[Date], [Date].[Calendar].currentmember is [Date].[Calendar].currentmember.parent.lastchild) } ON ROWS

FROM [Adventure Works]

If hierarchy is ...-Months-...-Days

SELECT

NON EMPTY { [Measures].[Sales Amount]...