I have 5 fields.
One is called "Billed Total" and it is in a db called "Packing Slips"
4 are in a db called "Customers" and they are our salespeople
These 2 databases are related through a common feild of "Company" and according to what salesperson is assigned to the company, the salesperson's name shows up on the invoice.
The Billed Total does not have anything to do with the salesperson, it is just a calculation based on how much product shipped out x the price per unit.
I've set up calculations before that shows our sales per week and per month, but is it possible to show an indidual salesperons sales per day, week, month through a calcualtion?
Yes, but I recommend a new table with one record for each salesperson. Then you can build relationships that link your sales personnel to your packing slips. Your calculation fields will then refer to these relationships in order to compute the desired answer.
You'll need multiple pairs of fields in your relationships. One pair will identify the salesperson in each table (packing slips and SalesPersons). You'll need to add a salesperson field to your packing slip records or do something creative with your company ID field. Another pair will match by date interval. There are date calculation fields that can return just the month, week or year portion of date.
Once your relationships are in place, the Sum() function can give you the total of all matching values in the packing slip table.
There are many variations of this technique possible. The details depend on your business model, the specific report/layout format and how you choose to structure your database.