總和 每三天計算一次 (11031)

 

 D2{=IF((MOD(ROUND(SUM(1/COUNTIF(B$2:B2,B$2:B2)),),3)=0)*(B2<>B3),SUM(OFFSET(C2,,,MAX(LOOKUP(1,0/(D$1:D1<>""),ROW($1:1))-ROW(A1)-1))),"")