Summarizing By Date

I have a basic bookkeeping workbook with multiple sheets each representing a differenct account. In each sheet, an entry is entered on a row with main columns being date, credit (where a positive amount goes), debit (negative amount goes), and then a series of columns representing the type of credit or debit where a simple "x" is placed.

This style has worked well in the past becuase we merely just sort by column and the "x"s clump all credit or debit types together and we just sum them at years end.

However, we are now trying to have the numbers report to a main sheet that will summarize them monthly; basically where the first column is all the different types of credits and debits and the next 12 columns are the months.

We know how to refference the other sheet to get the data, but where it gets complicated is summarizing ALL the sheets together since they all have varying number of entires per month.

Is there some sort of way I can write a formula (or series of formualas) that will allow it to collect all the data from one sheet by only looking at the month column, and add that up, and then do the same for each sheet?