看我的抓圖：
統計該月周壹至周四：
=SUMPRODUCT((MONTH(A$1:A$100)=MONTH(TODAY()))*(WEEKDAY(A$1:A$100,2)>0)*(WEEKDAY(A$1:A$100,2)<5))
統計該月周五：
=SUMPRODUCT((MONTH(A$1:A$100)=MONTH(TODAY()))*(WEEKDAY(A$1:A$100,2)=5))
統計該月周六日：
=SUMPRODUCT((MONTH(A$1:A$100)=MONTH(TODAY()))*(WEEKDAY(A$1:A$100,2)>5)*(WEEKDAY(A$1:A$100,2)<=7))