Customer Credit Summary: Average Days To Pay

I received an email today with a query on GP's "Average Days To Pay" on a Customer's Credit Summary. Query is : How GP calculates Average Days To Pay for a customer? According to GP's Receivables Management user manual: After a customer has paid his or her first invoice, the average days to pay (ADTP) is calculated based on the number of invoices a customer has, the time taken to pay the first invoice, and the time taken to pay the most recent invoice. The formula for calculating more