=COUNTIF(A:A,the_test_date)*weight

will do a simple calculation, but if you want to store all the weights and
dates in arrays, and calculate and sum in one step, you could use

=SUMPRODUCT(COUNTIF(A2:A20,H1:H3)*I1:I3)

--
HTH

Bob Phillips

(replace somewhere in email address with gmail if mailing direct)

"Hendrik" wrote in message
...
COUNTIF provide me with the amount of times a number was used in a
column.I
now want to add weight to the different time position s of the spesific
number/s by introducing a column with values according to date and
multiplying the specific number by the weight and adding the totals so as
to
compare the values historic significance.