If you can derive a column's value from an existing column, generally you would just do this in a query, not add it to a table. Start up a new query, add the table in question to it and use a Format function to convert the field with the date into a month (look up in Help for the syntax). You can then use this as the basis for any forms/ reports that you need. If you're not sure about any of this, please repost with the name of your table and the names of the fields within it.