I am trying to do a formula that will add up all the values for each part
sold in a specify period.

worksheet is column based , 10000 lines of various different part numbers in
column A, 10000 different sales values column D and 365 different dates
invoiced column H.

I need to break this down to how much each part generated in each quarter eg
today()-90, today())-180 , today()-270, today()-365

please help as I really am stuck on this , im thinking of the lines of a
sumproduct approach, but just cant quite sort it out in my head, many thanks

I would prefer email to my home adress as I can
access this at any time through the day

andy