I have a spreadsheet that I use SUMPRODUCT or SUMIFS to summarise data into a
consolidation sheet. The data that I need to summarise has the following
columns (amongst others) that need to be taken into account:
Date (if the date falls into the month of September, then the data is summed
in the September column)
Classification (there are four classification types)
Amount (the amount that is summed)

Everything works brilliantly except my staff cannot use the spreadsheet
because they are too resource heavy.

I heard about Pivot Tables the other day and tried one out. It is
summarising the data how I would like it, but it uses every day as a criteria
and I cant work out how to summarise that data for say September in a
September column instead of summarising it for every day it finds in September

Any ideas?