DATEDIF(G15,/8/31","Y")&"歲"&DATEDIF(G15,/8/31","YM")&"月"&DATEDIF(G15,/8/31","MD")
或
=TEXT(DATEDIF(G15,/8/31","D"),"YY歲M月D日")
公式中的/8/31"換成該日期所在單元格。