HI

I got a table

where column 1 is a list of sorted dates ( with gaps between the dates )
column 4 has a list of value's

I want to collect the values sum of a specific weeknumber.

I would like to use

sumif(columnOfDates; weeknumber; columnOfValues)

sumif ( weeknumber(A5:A10);10; D5:D10) doesn't work. Did try shift control enter but didn't also. Also SumiffS, or I do something wrong actualy I hope.

Question
Is weekday not usable as an array function?If yes how to use it?
How to solve this?

I can use a second weeknumber column, but like to avoid unneeded column.