Can someone please help me modify this sum product average formula (currently for months) - to calculate weekly averages?
=SUM(IF(FREQUENCY(IF((ROUNDUP(MONTH($A$2:$A$100)/3,0)=MID(AG$4,2,1)+0)*(YEAR($A$2:$A$100)=VALUE(RIGHT(AG$4,4)))*($C$2:$C$100=AG$5),MONTH($A$2:$A$100)),{1,2,3,4,5,6,7,8,9...