GET Months in Data Range

Hello everyone,

I have some date, let's say (01/01/11..31/12/11) for hole year, and to get for each month the date(for January is 01/01/11..31/01/11, for February it depends is it 28 days or 29 days the month).

I am trying to make a report with columns Purchased QTY, Sales QTY and Inventory at the end of month, for each month these columns.

Need Help,

Thanks for your advice.