Difference between dates not displaying correctly?

[Quartekoen]

Hello, everyone.

At the place I work, we have a database for the invoices that we send to customers, and another database for the payments we receive for those invoices. We are interested in figuring out how long, on average, it takes each of our customers to pay us back.

I've added a field to our invoice database, which is calculated as follows

Invoices::DaysToPay = Payments::Date - Invoices::Date

This should result in the number of days between when the invoice was issued, and when it was paid.

Next, in our customer file, we have this calculated field

Customer::AvgPaymentDays = Avg( Invoices::DaysToPay )

Where Customer is related to Invoices by the CustomerID. Theoretically, this should give me the average number of days that this customer takes to pay their invoices. On my computer, it does just that. However, on any other computer, running the same version of FileMaker, logged into the same account, the number is different. Instead of saying, for example, 36, it says -733863.

All the calculations fields are set to result as a number. There are no other calculations in play. I don't know what's going on here.

Any suggestions?

Regards.

[comment]

Well, -733863 is what you would get if you subtracted the date of April 1, 2010 from zero. So I guess you have a problem with the data in the Payments::Date field.