I have a spreadsheet with 3 repeated rows - Quantity, Total Price, Unit Price. Next to Quantity is a cell with the date. In my example A10 = Date, C10 = Quantity, C11 = Total Price, C12 = Unit Price. I am looking for a formula to sum all Quantity values. For the sake of trying to get the formula right, I have been using two sets of data A10:C15...but this will go on without end.

I can get an array formula to sum by month ={SUM(IF(MONTH(A10:A15)=11,C10:C15,""))}

I can get an array formula to sum by year {=SUM(IF(YEAR(A10:A15)=2016,C10:C15,""))}

I cannot get one to sum by both...I have tried, without success ={SUM(IF(AND(MONTH(A10:A15)=11,YEAR(A10:A15)=2016),C10:C15,""))}

Any ideas? Thanks in advance.

(also...my first post...hopefully I met all the rules/criteria for a good post!)

TC