The desired enhancement to the average days to pay calculation as part of the credit management feature:

See Average payment days as 3 mo and 6 mo figures in addition to the current 12 mo figure
See Weighted average payment days as 3 mo, 6 mo, and 12 mo figures
For the weighted calculation, we want to multiply the "weight of the invoice" times the days.

Here is an example below:
$10 invoice paid in 5 days
$100 invoice paid in 10 days
Total invoice value = $110
Unweighted average days to pay = 10 days + 5 days / 2 = 7.5 days

Weighted average days to pay =((Invoice 1 value / Invoice total) * days for invoice 1) + ((Invoice 2 value / Invoice total) * days for invoice 2)

(($10 / $110) * 5) + (($100 / $110) * 10) = 9.55 days