if GroupName ({INVOICE.DATE}, "monthly") =  "1/2009" then
Count ({INVOICE.TRANSNBR}, {INVOICE.DATE}, "monthly")/22 else
if GroupName ({INVOICE.DATE}, "monthly") =  "2/2009" then
Count ({INVOICE.TRANSNBR}, {INVOICE.DATE}, "monthly")/20 else
if GroupName ({INVOICE.DATE}, "monthly") =  "3/2009" then
Count ({INVOICE.TRANSNBR}, {INVOICE.DATE}, "monthly")/23 else
if GroupName ({INVOICE.DATE}, "monthly") =  "4/2009" then
Count ({INVOICE.TRANSNBR}, {INVOICE.DATE}, "monthly")/20 else
if GroupName ({INVOICE.DATE}, "monthly") =  "5/2009" then
Count ({INVOICE.TRANSNBR}, {INVOICE.DATE}, "monthly")/21 else
if GroupName ({INVOICE.DATE}, "monthly") =  "6/2009" then
Count ({INVOICE.TRANSNBR}, {INVOICE.DATE}, "monthly")/22 else
if GroupName ({INVOICE.DATE}, "monthly") =  "7/2009" then
Count ({INVOICE.TRANSNBR}, {INVOICE.DATE}, "monthly")/20 else
if GroupName ({INVOICE.DATE}, "monthly") =  "8/2009" then
Count ({INVOICE.TRANSNBR}, {INVOICE.DATE}, "monthly")/23 else
if GroupName ({INVOICE.DATE}, "monthly") =  "9/2009" then
Count ({INVOICE.TRANSNBR}, {INVOICE.DATE}, "monthly")/20 else
if GroupName ({INVOICE.DATE}, "monthly") =  "10/2009" then
Count ({INVOICE.TRANSNBR}, {INVOICE.DATE}, "monthly")/22 else
if GroupName ({INVOICE.DATE}, "monthly") =  "11/2009" then
Count ({INVOICE.TRANSNBR}, {INVOICE.DATE}, "monthly")/20 else
if GroupName ({INVOICE.DATE}, "monthly") =  "12/2009" then
Count ({INVOICE.TRANSNBR}, {INVOICE.DATE}, "monthly")/20

 

How do I calculate week?

 

Month was a simple distinct count because I have the invoices running for 1 month period in select expert.