Thankyou! That's just the pointer I needed - have been working with it over
the weekend and the sumproduct is good, thanks! Go well.

"vezerid" wrote:

Assuming dates in A2:A10, quantities in B2:B10. Further assuming
StartDate in G1, EndDate in G2.

=SUMPRODUCT(B2:B1, --(A2:A10=G1), --(A2:A10<=G2))

HTH
Kostis Vezerides