Example assumption: You have entered invoices into a table. Column A contains the date value of the invoice, column B the amounts. You want to find a formula that you can use to return the total of all amounts only for a specific month, e.g. only the amount for the period >=2008-01-01 to <2008-02-01. The range with the date values covers A1:A40, the range containing the amounts to be totaled is B1:B40. C1 contains the start date, 2008-01-01, of the invoices to be included and C2 the date, 2008-02-01, that is no longer included.