Moises,

In addition to what George and Cindy said, some people store receipt date as string. When you can easily select records by day (WHERE ReceiptDate = '20010618'), by month (WHERE ReceiptDate = '200106') or by year (WHERE ReceiptDate = '2001'). If you wish to have a quarter reports, then receipt month may be encoded using quarter number and month number in quarter (Jan2001 = '200111', Jun2001 = '200123').

>To control money amount per month at a shop,
> Whats programatically more correct and usual
> Create only a table to control all months
> Or create a new table every month ?
> Jan_2001.dbf
> Feb_2001.dbf
> etc...