It is a known issue that the "Avg Days Pay YTD" field in the customer file may not be correct. There are various reasons for the average days pay not to calculate correctly. One reason is that this field, as it was originally designed, does not support decimals. So if you have a customer that you do a lot of business with, the calculation will start to become inaccurate because of the rounding problem. The good news is there is a utility to address this issue. You can go to Main Menu -> Util-Setup -> Global Setup -> Utilities -> Generate Statistic Info -> Generate -> Recalc Customer Avg Days Pay.

If you do not feel comfortable making a global change, you can just recalculate one customer at a time and see if the new value makes sense for you. When it comes to choosing between Fiscal or Calendar Year, most of you will use "C" for calendar. However, if you are indeed using the Fiscal year, then enter "F" and then enter the "Current Fiscal Year Start Date."  This utility will review records in both A/R Open Item File and A/R Open Item History when calculating this number. This utility will print the details of A/R Open item to show the calculation basis. Some of our users choose to make this a deferred process that runs every night. The following information will be updated in the customer file after you run this utility:

* Avg Days Pay YTD
* Avg Days Pay Last YR
* Invoices Pd Ytd

Before you run this utility, there is a global setup flag related to this utility that you should check. Go to Main Menu -> Util-Setup -> Global Setup -> Acct -> A/R Global Control,
20. Calc Avg Days Pay YTD Base on Inv or Due Date. The default is "I" (Invoice Date). You have the option of changing it to "D" (Due Date). If it is based on due date, then the Avg Day Pay YTD may contain a negative value. If a customer pays their invoice before the due date, then the field will show negative days. You might want to consider using Due Date if you often negotiate with customers regarding terms on an individual order basis.