Calculationg number of items sold after a specific date

Hi Guys

I am trying to calculate for each row in a spreadhseet, how many items have been sold after a specific week ending date.

I have attached an example to make it easier to understand.

Column T in the spreadsheet specifies that from which week ending date that I want to calculate how many items have been sold. I then need the value returning in the yellow cell for each of the rows.

Any help would be much appreciated.

Cheers

This doesnt seem to be returning the no of items sold after the specided week ending date at the end of each row.